diff --git a/chrome/content/zotero/xpcom/data/cachedTypes.js b/chrome/content/zotero/xpcom/data/cachedTypes.js
index 4568237d0..be3e04381 100644
--- a/chrome/content/zotero/xpcom/data/cachedTypes.js
+++ b/chrome/content/zotero/xpcom/data/cachedTypes.js
@@ -106,7 +106,6 @@ Zotero.CachedTypes = function() {
 		
 		if (!this._types['_' + idOrName]) {
 			Zotero.debug('Invalid ' + this._typeDesc + ' ' + idOrName, 1);
-			Zotero.debug((new Error()).stack, 1);
 			return false;
 		}
 		
@@ -510,14 +509,14 @@ Zotero.CharacterSets = new function() {
 		name = name.toLowerCase();
 		
 		// Don't allow too-long or non-ASCII names
-		if (name.length > 50 || !name.match(/[^a-z0-9\-_]/)) {
+		if (name.length > 50 || !name.match(/^[a-z0-9\-_]+$/)) {
 			return false;
 		}
 		
 		var sql = "INSERT INTO " + this._table + " (" + this._nameCol + ") VALUES (?)";
 		yield Zotero.DB.queryAsync(sql, name);
 		
-		sql = "SELECT id FROM " + this._table + " WHERE " + this._nameCol + "=?";
+		sql = "SELECT " + this._idCol + " FROM " + this._table + " WHERE " + this._nameCol + "=?";
 		var id = yield Zotero.DB.valueQueryAsync(sql, name);
 		
 		this._cacheTypeData({
diff --git a/test/tests/itemTest.js b/test/tests/itemTest.js
index d02d50aae..19fa7bbeb 100644
--- a/test/tests/itemTest.js
+++ b/test/tests/itemTest.js
@@ -201,6 +201,31 @@ describe("Zotero.Item", function () {
 		});
 	});
 	
+	describe("#attachmentCharset", function () {
+		it("should get and set a value", function* () {
+			var charset = 'utf-8';
+			var item = new Zotero.Item("attachment");
+			item.attachmentLinkMode = Zotero.Attachments.LINK_MODE_IMPORTED_FILE;
+			item.attachmentCharset = charset;
+			var itemID = yield item.save();
+			item = yield Zotero.Items.getAsync(itemID);
+			assert.equal(item.attachmentCharset, charset);
+		})
+		
+		it("should not be marked as changed if not changed", function* () {
+			var charset = 'utf-8';
+			var item = new Zotero.Item("attachment");
+			item.attachmentLinkMode = Zotero.Attachments.LINK_MODE_IMPORTED_FILE;
+			item.attachmentCharset = charset;
+			var itemID = yield item.save();
+			item = yield Zotero.Items.getAsync(itemID);
+			
+			// Set charset to same value
+			item.attachmentCharset = charset
+			assert.isFalse(item.hasChanged());
+		})
+	})
+	
 	describe("#attachmentFilename", function () {
 		it("should get and set a filename for a stored file", function* () {
 			var filename = "test.txt";