Firefox Hang Fixes
From SnOwy - Ed's Wiki Notebook
Occasionally applications in OS X will behave oddly and the problem is difficult to trace.
Firefox hung while trying to use the "Save as..." dialogue box, which means that something's wrong with the Firefox application, the Operating System or the Preferences.
The two things it's least likely to be are the Application and OS. These items aren't open for write access whilst Firefox is running.
The following is the procedure I'd recommend (based on trial and error)-- only advance to the next point when the present point fails to provide relief.
- Deactivate or uninstall any suspect plug-ins
- Delete Firefox from the Application Folder (OS X) OR Uninstall Firefox (Windows)
- Delete "~/Library/Application Support/Firefox" (OS X) OR Purge the current user profile (Windows)
- Clean out the registry (Windows)
- Return to the most recent restore point (Windows)
- Reinstall the OS (OS X / Windows 9x, 2K or XP only)
OS X has the added benefit of restoring user accounts and applications after a reinstallation of the operating system, this makes the step relatively cheap. Consider it a last alternative though. Windows users should consider making restore points when the system is fine as reinstalling the OS is functionally the same as reformatting the hard drive (expensive).
Update
The source of the hang was some bizarre entry cached within "~/Library/Application Support/Firefox" corresponding to a network volume that was no longer available.
