If an updated extension ceases to use a chrome overlay file and doesn't include it in the jar file for the new release Firefox will hang. What appears to be the problem is that version 1 of the extension specifies a xul file, when the extension is updated to version 2 Firefox will add a reference to new xul overlay files in the chrome\overlayinfo\browser\content\overlays.rdf file in the Profile but it won't remove references to xul files that were used in version 1 but not in version 2. So when Firefox loads it can't find the old xul file in the new jar file and hangs. I'm going to attach two versions of a test extension that demonstrates this; the extension just displays an alert when a window is opened. Start with a clean profile and apply version 1 and then later apply version 2 on top of that and Firefox will hang. If you install version 2 directly without ever having applied version 1 then there won't be a problem.
Confirmed with the following trunk build. Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.8a6) Gecko/20041216 Firefox/1.0+ (stipe)
I thought I saw it reported, but couldn't find it.
This bug is no longer on trunk. testextension_1.0.xpi chrome.manifest: overlay chrome://browser/content/browser.xul chrome://testextension/content/testextension.xul testextension_1.1.xpi chrome.manifest: overlay chrome://browser/content/browser.xul chrome://testextension/content/testextension-new.xul -> updated properly Mozilla/5.0 (Windows; U; Windows NT 5.0; en-US; rv:1.8b2) Gecko/20050403 Firefox/1.0+
I believe this was fixed by the chrome reg rewrite a while back. This is wfm as well.