diff --git a/chrome/content/zotero/xpcom/data/dataObject.js b/chrome/content/zotero/xpcom/data/dataObject.js
index fbea2806e0..08b335789a 100644
--- a/chrome/content/zotero/xpcom/data/dataObject.js
+++ b/chrome/content/zotero/xpcom/data/dataObject.js
@@ -142,22 +142,12 @@ Zotero.DataObject.prototype._set = function (field, value) {
 
 
 Zotero.DataObject.prototype._setIdentifier = function (field, value) {
-	// If primary data is loaded, the only allowed identifier change is libraryID
-	// (allowed mainly for the library switcher in the advanced search window),
-	// and then only for unsaved objects (i.e., those without an id or key)
-	if (this._loaded.primaryData) {
-		if (field != 'libraryID' || this._id || this._key) {
-			throw new Error("Cannot set " + field + " after object is already loaded");
-		}
-	}
-	
 	switch (field) {
 	case 'id':
 		if (this._key) {
 			throw new Error("Cannot set id if key is already set");
 		}
 		value = Zotero.DataObjectUtilities.checkDataID(value);
-		this._identified = true;
 		break;
 		
 	case 'libraryID':
@@ -172,13 +162,29 @@ Zotero.DataObject.prototype._setIdentifier = function (field, value) {
 			throw new Error("Cannot set key if id is already set");
 		}
 		value = Zotero.DataObjectUtilities.checkKey(value);
-		this._identified = true;
 	}
 	
 	if (value === this['_' + field]) {
 		return;
 	}
 	
+	// If primary data is loaded, the only allowed identifier change is libraryID, and then only
+	// for unidentified objects, and then only either if a libraryID isn't yet set (because
+	// primary data gets marked as loaded when fields are set for new items, but some methods
+	// (setCollections(), save()) automatically set the user library ID after that if none is
+	// specified), or for searches (for the sake of the library switcher in the advanced search
+	// window, though that could probably be rewritten)
+	if (this._loaded.primaryData) {
+		if (!(!this._identified && field == 'libraryID'
+				&& (!this._libraryID || this._objectType == 'search'))) {
+			throw new Error("Cannot change " + field + " after object is already loaded");
+		}
+	}
+	
+	if (field == 'id' || field == 'key') {
+		this._identified = true;
+	}
+	
 	this['_' + field] = value;
 }
 
@@ -624,7 +630,7 @@ Zotero.DataObject.prototype.save = Zotero.Promise.coroutine(function* (options)
 	
 	try {
 		if (Zotero.DataObject.prototype._finalizeSave == this._finalizeSave) {
-			throw new Error("_finalizeSave not implement for Zotero." + this._ObjectType);
+			throw new Error("_finalizeSave not implemented for Zotero." + this._ObjectType);
 		}
 		
 		env.notifierData = {};
@@ -687,7 +693,7 @@ Zotero.DataObject.prototype.hasChanged = function() {
 Zotero.DataObject.prototype._initSave = Zotero.Promise.coroutine(function* (env) {
 	// Default to user library if not specified
 	if (this.libraryID === null) {
-		this.libraryID = Zotero.Libraries.userLibraryID;
+		this._libraryID = Zotero.Libraries.userLibraryID;
 	}
 	
 	env.isNew = !this.id;
diff --git a/chrome/content/zotero/xpcom/data/item.js b/chrome/content/zotero/xpcom/data/item.js
index e9e261118e..c3f2aced9a 100644
--- a/chrome/content/zotero/xpcom/data/item.js
+++ b/chrome/content/zotero/xpcom/data/item.js
@@ -315,137 +315,64 @@ Zotero.Item.prototype.loadFromRow = function(row, reload) {
 }
 
 Zotero.Item.prototype._parseRowData = function(row) {
-	if (false) {
-		var primaryFields = this.ObjectsClass.primaryFields;
-		for (let i=0; i<primaryFields.length; i++) {
-			if (primaryFields[i] === undefined) {
-				Zotero.debug('Skipping missing field ' + primaryFields[i]);
-				continue;
-			}
+	var primaryFields = this.ObjectsClass.primaryFields;
+	for (let i=0; i<primaryFields.length; i++) {
+		let col = primaryFields[i];
+		
+		if (row[col] === undefined) {
+			Zotero.debug('Skipping missing field ' + col);
+			continue;
 		}
 		
-		if (row.itemID !== undefined) {
-			this._id = parseInt(row.itemID);
-		}
-		if (row.itemTypeID !== undefined) {
-			this._id = parseInt(row.itemTypeID);
-		}
-		if (row.libraryID !== undefined) {
-			this._libraryID = parseInt(row.libraryID);
-		}
-		if (row.key !== undefined) {
-			this._key = row.key;
-		}
-		if (row.dateAdded !== undefined) {
-			this._dateAdded = row.dateAdded;
-		}
-		if (row.dateModified !== undefined) {
-			this._dateModified = row.dateModified;
-		}
-		if (row.version !== undefined) {
-			this._version = parseInt(row.version);
-		}
-		if (row.numNotes !== undefined) {
-			this._numNotes = parseInt(row.numNotes);
-		}
-		if (row.numNotesTrashed !== undefined) {
-			this._numNotesTrashed = parseInt(row.numNotesTrashed);
-		}
-		if (row.numNotesEmbedded !== undefined) {
-			this._numNotesEmbedded = parseInt(row.numNotesEmbedded);
-		}
-		if (row.numNotesEmbeddedTrashed !== undefined) {
-			this._numNotesEmbeddedTrashed = parseInt(row.numNotesEmbeddedTrashed);
-		}
-		if (row.numAttachments !== undefined) {
-			this._numAttachments = parseInt(row.numAttachments);
-		}
-		if (row.numAttachmentsTrashed !== undefined) {
-			this._numAttachmentsTrashed = parseInt(row.numAttachmentsTrashed);
-		}
-		if (row.parentKey !== undefined) {
-			this._parentKey = row.parentKey || false;
-		}
-		if (row.parentID !== undefined) {
-			this._parentID = row.parentID ? parseInt(row.parentID) : false;
-		}
-		if (row.synced !== undefined) {
-			this._synced = !!row.synced;
-		}
-		if (row.firstCreator !== undefined) {
-			this._firstCreator = row.firstCreator ? row.firstCreator : '';
-		}
-		if (row.sortCreator !== undefined) {
-			this._sortCreator = row.sortCreator ? row.sortCreator : '';
-		}
-		if (row.attachmentCharset !== undefined) {
-			this._attachmentCharset = row.attachmentCharset ? row.attachmentCharset : null;
-		}
-		if (row.attachmentLinkMode !== undefined) {
-			this._attachmentLinkMode = parseInt(row.attachmentLinkMode);
-		}
-		if (row.attachmentContentType !== undefined) {
-			this._attachmentContentType = row.attachmentContentType ? row.attachmentContentType : '';
-		}
-		if (row.attachmentPath !== undefined) {
-			this._attachmentPath = row.attachmentPath ? row.attachmentPath : '';
-		}
-		if (row.attachmentSyncState !== undefined) {
-			this._attachmentSyncState = parseInt(row.attachmentSyncState);
-		}
-	}
-	else {
-		var primaryFields = this.ObjectsClass.primaryFields;
-		for (let i=0; i<primaryFields.length; i++) {
-			let col = primaryFields[i];
+		let val = row[col];
+		
+		//Zotero.debug("Setting field '" + col + "' to '" + val + "' for item " + this.id);
+		
+		switch (col) {
+			// Unchanged
+			case 'itemID':
+				col = 'id';
+				break;
+				
+			case 'libraryID':
+				break;
 			
-			if (row[col] === undefined) {
-				Zotero.debug('Skipping missing field ' + col);
-				continue;
-			}
+			// Integer or 0
+			case 'version':
+			case 'numNotes':
+			case 'numNotesTrashed':
+			case 'numNotesEmbedded':
+			case 'numNotesEmbeddedTrashed':
+			case 'numAttachments':
+			case 'numAttachmentsTrashed':
+				val = val ? parseInt(val) : 0;
+				break;
 			
-			let val = row[col];
+			// Value or false
+			case 'parentKey':
+				val = val || false;
+				break;
 			
-			//Zotero.debug("Setting field '" + col + "' to '" + val + "' for item " + this.id);
-			switch (col) {
-				case 'itemID':
-					this._id = val;
-					break;
+			// Integer or false if falsy
+			case 'parentID':
+				val = val ? parseInt(val) : false;
+				break;
+			
+			case 'attachmentLinkMode':
+				val = val !== null ? parseInt(val) : false;
+				break;
+			
+			// Boolean
+			case 'synced':
+			case 'deleted':
+				val = !!val;
+				break;
 				
-				case 'libraryID':
-					this['_' + col] = val;
-					break;
-				
-				case 'version':
-				case 'numNotes':
-				case 'numNotesTrashed':
-				case 'numNotesEmbedded':
-				case 'numNotesEmbeddedTrashed':
-				case 'numAttachments':
-				case 'numAttachmentsTrashed':
-					this['_' + col] = val ? parseInt(val) : 0;
-					break;
-				
-				case 'parentKey':
-					this['_parentKey'] = val || false;
-					break;
-				
-				case 'parentID':
-					this['_' + col] = val ? parseInt(val) : false;
-					break;
-				
-				case 'attachmentLinkMode':
-					this['_' + col] = val !== null ? parseInt(val) : false;
-					break;
-				
-				case 'synced':
-					this['_synced'] = !!val;
-					break;
-					
-				default:
-					this['_' + col] = val ? val : '';
-			}
+			default:
+				val = val ? val : '';
 		}
+		
+		this['_' + col] = val;
 	}
 }
 
@@ -3436,6 +3363,10 @@ Zotero.Item.prototype.getCollections = function () {
  * @param {Array<String|Integer>} collectionIDsOrKeys Collection ids or keys
  */
 Zotero.Item.prototype.setCollections = function (collectionIDsOrKeys) {
+	if (!this.libraryID) {
+		this.libraryID = Zotero.Libraries.userLibraryID;
+	}
+	
 	this._requireData('collections');
 	
 	if (!collectionIDsOrKeys) {
@@ -3469,6 +3400,10 @@ Zotero.Item.prototype.setCollections = function (collectionIDsOrKeys) {
  * @param {Number} collectionID
  */
 Zotero.Item.prototype.addToCollection = function (collectionIDOrKey) {
+	if (!this.libraryID) {
+		this.libraryID = Zotero.Libraries.userLibraryID;
+	}
+	
 	var collectionID = parseInt(collectionIDOrKey) == collectionIDOrKey
 			? parseInt(collectionIDOrKey)
 			: this.ContainerObjectsClass.getIDFromLibraryAndKey(this.libraryID, collectionIDOrKey)
@@ -3494,6 +3429,10 @@ Zotero.Item.prototype.addToCollection = function (collectionIDOrKey) {
  * @param {Number} collectionID
  */
 Zotero.Item.prototype.removeFromCollection = function (collectionIDOrKey) {
+	if (!this.libraryID) {
+		this.libraryID = Zotero.Libraries.userLibraryID;
+	}
+	
 	var collectionID = parseInt(collectionIDOrKey) == collectionIDOrKey
 			? parseInt(collectionIDOrKey)
 			: this.ContainerObjectsClass.getIDFromLibraryAndKey(this.libraryID, collectionIDOrKey)
diff --git a/test/tests/dataObjectsTest.js b/test/tests/dataObjectsTest.js
index ca917d73bb..fe0dfa00f2 100644
--- a/test/tests/dataObjectsTest.js
+++ b/test/tests/dataObjectsTest.js
@@ -43,4 +43,70 @@ describe("Zotero.DataObjects", function () {
 			}
 		});
 	});
+	
+	describe("#_setIdentifier", function () {
+		it("should not allow an id change", function* () {
+			var item = yield createDataObject('item');
+			try {
+				item.id = item.id + 1;
+			}
+			catch (e) {
+				assert.equal(e.message, "ID cannot be changed");
+				return;
+			}
+			assert.fail("ID change allowed");
+		})
+		
+		it("should not allow a key change", function* () {
+			var item = yield createDataObject('item');
+			try {
+				item.key = Zotero.DataObjectUtilities.generateKey();
+			}
+			catch (e) {
+				assert.equal(e.message, "Key cannot be changed");
+				return;
+			}
+			assert.fail("Key change allowed");
+		})
+		
+		it("should not allow key to be set if id is set", function* () {
+			var item = createUnsavedDataObject('item');
+			item.id = Zotero.Utilities.rand(100000, 1000000);
+			try {
+				item.libraryID = Zotero.Libraries.userLibraryID;
+				item.key = Zotero.DataObjectUtilities.generateKey();
+			}
+			catch (e) {
+				assert.equal(e.message, "Cannot set key if id is already set");
+				return;
+			}
+			assert.fail("ID change allowed");
+		})
+		
+		it("should not allow id to be set if key is set", function* () {
+			var item = createUnsavedDataObject('item');
+			item.libraryID = Zotero.Libraries.userLibraryID;
+			item.key = Zotero.DataObjectUtilities.generateKey();
+			try {
+				item.id = Zotero.Utilities.rand(100000, 1000000);
+			}
+			catch (e) {
+				assert.equal(e.message, "Cannot set id if key is already set");
+				return;
+			}
+			assert.fail("Key change allowed");
+		})
+		
+		it("should not allow key to be set if library isn't set", function* () {
+			var item = createUnsavedDataObject('item');
+			try {
+				item.key = Zotero.DataObjectUtilities.generateKey();
+			}
+			catch (e) {
+				assert.equal(e.message, "libraryID must be set before key");
+				return;
+			}
+			assert.fail("libraryID change allowed");
+		})
+	})
 })
diff --git a/test/tests/itemTest.js b/test/tests/itemTest.js
index c77ef9da4f..bee454cc9d 100644
--- a/test/tests/itemTest.js
+++ b/test/tests/itemTest.js
@@ -183,6 +183,26 @@ describe("Zotero.Item", function () {
 		})
 	})
 	
+	describe("#deleted", function () {
+		it("should be set to true after save", function* () {
+			var item = yield createDataObject('item');
+			item.deleted = true;
+			yield item.saveTx();
+			assert.ok(item.deleted);
+		})
+		
+		it("should be set to false after save", function* () {
+			var collection = yield createDataObject('collection');
+			var item = createUnsavedDataObject('item');
+			item.deleted = true;
+			yield item.saveTx();
+			
+			item.deleted = false;
+			yield item.saveTx();
+			assert.isFalse(item.deleted);
+		})
+	})
+	
 	describe("#parentID", function () {
 		it("should create a child note", function* () {
 			var item = new Zotero.Item('book');