WinRegInstallLocation in nsExtensionManager.js Hack
Firefox has a feature to add extensions that are defined in the Windows registry. Well, this is something that I definitely DO NOT want to happen when using portable firefox. It would be a nice feature to have a warning that registry extensions are available, and prompt the user to allow them to occur.
For the short term, I hacked the nsExtensionManager.js by commenting out the lines in the try block, and leaving the catch block alone in the WinRegInstallLocation function. Maybe this info can help somebody else too.