Comment 9 for bug 366103

There have been a lot of reports on this lately, it's not clear if there is a single cause or multiple causes. We could really use some QA help to take this seriously and track these issues down.

Once it happens you can't relaunch Firefox without finding the process and killing it -- a procedure that novice users are not going to manage. No doubt there are a lot of bugs something like "Firefox won't open anymore until I reboot".

Notice that there is a new Mozillazine article for this (bug 399392):
http://kb.mozillazine.org/Firefox.exe_always_open

Not sure if I should have just reuused the meta bug 239223 -- that's pretty old and seemed to be privacy/security related. We should take a closer look at the bugs listed there as well.