Looks like the failure to shut down problem is back again in Win7 WinXP with Firefox 12. Browser does not shut down completely all the time. Keeps running in the background and consumes more resources the longer it runs. When you try to start it again, the icon on the desktop highlights for a bit and then nothing happens. Happened with a previous version (Firefox 9 perhaps?) last July / August. Problem was fixed last year with an update. Suspected a memory leak at the time. Think your memory leak is back with Firefox 12. I can always shut it down via Task Manager in WinXP / Win7. Upon restart, sometimes it comes back with last page loaded instead of the home page. Doesn't seem to be tied to any plugin changes, as they have been pretty stable for the last 6 months. This is happening on two separate desktops. Cheers -