diff --git a/chrome/content/zotero/preferences/preferences.js b/chrome/content/zotero/preferences/preferences.js
index 151bfeddad..9e0be50e78 100644
--- a/chrome/content/zotero/preferences/preferences.js
+++ b/chrome/content/zotero/preferences/preferences.js
@@ -322,7 +322,7 @@ function verifyStorageServer() {
 	abortButton.hidden = false;
 	progressMeter.hidden = false;
 	
-	var requestHolder = Zotero.Sync.Storage.checkServer('webdav', function (uri, status, callback) {
+	var requestHolder = Zotero.Sync.Storage.checkServer('WebDAV', function (uri, status, callback) {
 		verifyButton.hidden = false;
 		abortButton.hidden = true;
 		progressMeter.hidden = true;
diff --git a/chrome/content/zotero/xpcom/storage.js b/chrome/content/zotero/xpcom/storage.js
index d7c0208d74..0170240b86 100644
--- a/chrome/content/zotero/xpcom/storage.js
+++ b/chrome/content/zotero/xpcom/storage.js
@@ -826,12 +826,17 @@ Zotero.Sync.Storage = new function () {
 			onSuccess: function () {},
 			onError: function (e) {
 				Zotero.debug(e, 1);
-				callback(null, null, e);
-				throw (e);
+				callback(null, null, function () {
+					// If there's an error, just display that
+					Zotero.Utilities.Internal.errorPrompt(Zotero.getString('general.error'), e);
+				});
+				return true;
 			}
-		});
+		}, false, "checkServer");
 		return module.checkServer(function (uri, status) {
-			callback(uri, status, module.checkServerCallback);
+			callback(uri, status, function () {
+				module.checkServerCallback(uri, status);
+			});
 		});
 	}
 	
@@ -845,7 +850,7 @@ Zotero.Sync.Storage = new function () {
 			onError: function (e) {
 				error(e);
 			}
-		});
+		}, false, "purgeDeletedStorageFiles");
 		module.purgeDeletedStorageFiles(callback);
 	}
 	
@@ -859,7 +864,7 @@ Zotero.Sync.Storage = new function () {
 			onError: function (e) {
 				error(e);
 			}
-		});
+		}, false, "purgeOrphanedStorageFiles");
 		module.purgeOrphanedStorageFiles(callback);
 	}
 	
diff --git a/chrome/content/zotero/xpcom/storage/module.js b/chrome/content/zotero/xpcom/storage/module.js
index d410b8ccfb..fc32d83c81 100644
--- a/chrome/content/zotero/xpcom/storage/module.js
+++ b/chrome/content/zotero/xpcom/storage/module.js
@@ -163,7 +163,7 @@ Zotero.Sync.Storage.Module.prototype.checkServer = function (callback) {
 
 Zotero.Sync.Storage.Module.prototype.checkServerCallback = function (uri, status, window, skipSuccessMessage) {
 	try {
-		return this._module.checkServerCallback(uri, status, authRequired, window, skipSuccessMessage);
+		return this._module.checkServerCallback(uri, status, window, skipSuccessMessage);
 	}
 	catch (e) {
 		Zotero.Sync.Storage.EventManager.error(e);