diff --git a/.hgtags b/.hgtags
--- a/.hgtags
+++ b/.hgtags
@@ -3,8 +3,9 @@ 7cd75dde674bf8e41411c96d10112695346a3cdd
 dc35ef559785fd1b03969609cd684dbf03d8e5b5 CHATZILLA_0_9_86_RELEASE
 1570a209115302bfc294e0faa5df2a8e08cfa416 CHATZILLA_0_9_85_RELEASE
 2167b379b64d61255cc12f1af2984958c44a4980 SEA_2_6_BASE
 8d4bc132f2523993a7d9c5a01cb94ef1048591b9 CHATZILLA_0_9_88_RELEASE
 0b5f5c3d666be70d5a1fc9aea562d39adf8fa181 CHATZILLA_0_9_88_1_RELEASE
 7a5400416482ab079fd0073dafa0a5b0382d7eaf CHATZILLA_0_9_88_2_RELEASE
 fc5089117b1413b53ce57d201ed0005babbd3280 CHATZILLA_0_9_89_RELEASE
 7f32a1339f8c334b6d731ec4972faa7a412c1667 CHATZILLA_0_9_90_RELEASE
+22bcb0f2601112cf039e33f4faad9ce802a97b0e CHATZILLA_0_9_91_RELEASE
diff --git a/xpi/resources/install.rdf b/xpi/resources/install.rdf
--- a/xpi/resources/install.rdf
+++ b/xpi/resources/install.rdf
@@ -67,16 +67,17 @@
     <em:contributor>Robert Ginda</em:contributor>
     <em:contributor>Gijs Kruitbosch</em:contributor>
     <em:contributor>James Ross</em:contributor>
     <em:contributor>Samuel Sieb</em:contributor>
     <em:iconURL>chrome://chatzilla/skin/images/logo.png</em:iconURL>
     <em:homepageURL>http://chatzilla.hacksrus.com/</em:homepageURL>
     <em:aboutURL>chrome://chatzilla/content/about/about.xul</em:aboutURL>
     <em:optionsURL>chrome://chatzilla/content/config.xul</em:optionsURL>
+    <em:multiprocessCompatible>true</em:multiprocessCompatible>
 
     <!-- package files -->
     <em:file>
       <Description about="urn:mozilla:extension:file:chatzilla.jar">
         <em:package>content/chatzilla/</em:package>
         <em:package>content/chatzilla/ff/</em:package>
         <em:locale>locale/en-US/chatzilla/</em:locale>
         <em:skin>skin/modern/chatzilla/</em:skin>
diff --git a/xul/content/handlers.js b/xul/content/handlers.js
--- a/xul/content/handlers.js
+++ b/xul/content/handlers.js
@@ -53,17 +53,18 @@ function onLoad()
     dd ("Initializing ChatZilla {");
     try
     {
         init();
     }
     catch (ex)
     {
         dd("caught exception while initializing:\n" + dumpObjectTree(ex));
-        showErrorDlg(formatException(ex) + "\n" + dumpObjectTree(ex));
+        var exception = formatException(ex) + (ex.stack && "\n" + ex.stack);
+        showErrorDlg(exception + "\n" + dumpObjectTree(ex));
     }
 
     dd("}");
     mainStep();
 }
 
 function initHandlers()
 {