Firefox 1.0PR (Linux version) has the annoying habit of dying out on me when I click on a link that opens a popup window. This doesn't happen always, but more than half the time. I would have reported this to Bugzilla, but it asked me to jump through so many hoops before accepting a bug report that I lost interest. There is supposed to be a Quality Agent that should kick in when an exception occurs, but no evidence of this so far. The saving grace is that at least the "Profile in use" message doesn't appear when I restart Firefox after the crash [*].

[*] Useful tip to remember: if you get this message after a crash, delete the file called 'lock' in the Firefox profile directory (usually ~/.mozilla/firefox/*default*)

Update: this problem vanished when I moved to Suse 9.1; however I had to fix another issue before I could get Firfox to work in Suse.

Update #2: Nope, the problem still persists, though on a random basis. But at least the Quality Feeback Agent faithfully calls home and whines about the problem now.