diff --git a/chrome/content/zotero/zoteroPane.js b/chrome/content/zotero/zoteroPane.js
index 9a5bea846..61dd79450 100644
--- a/chrome/content/zotero/zoteroPane.js
+++ b/chrome/content/zotero/zoteroPane.js
@@ -3386,15 +3386,21 @@ var ZoteroPane = new function()
 					this.loadURI(url, event, { attachmentID: itemID});
 				}
 				else {
-					// Some platforms don't have nsILocalFile.launch, so we just load it and
+					// Some platforms don't have nsILocalFile.launch, so we just
 					// let the Firefox external helper app window handle it
 					try {
 						file.launch();
 					}
 					catch (e) {
-						Zotero.debug("launch() not supported -- passing file to loadURI()");
-						var fileURL = attachment.getLocalFileURL();
-						this.loadURI(fileURL);
+						Zotero.debug("launch() not supported -- passing file to loadUrl()");
+						
+						var uri = Components.classes["@mozilla.org/network/standard-url;1"].
+									createInstance(Components.interfaces.nsIURI);
+						uri.spec = attachment.getLocalFileURL();
+						
+						var nsIEPS = Components.classes["@mozilla.org/uriloader/external-protocol-service;1"].
+										getService(Components.interfaces.nsIExternalProtocolService);
+						nsIEPS.loadUrl(uri);
 					}
 				}
 			}