Firefox is already running. . .
 

When I close firefox completly, that is "X-ing out", then I try to open it again, it says an instance of firefox is already running, and that I've got to exit that first. There's no window open, but for some reason there's a firefox process, so I killall firefox-bin, and it starts fine.

What can I do to fix this, and why is it happening?

Thanks :)

I had the same problem sometimes. In my case there was even no firefox or firefox-bin process running. Then I found, that in the .mozilla/firefox... directory there was a file existing suddenly called "lock". Deleting the file and everything went fine. But I don't really know why firefox does this bad thing.

You did the right thing. Delete the lock file if FF hangs.
Can't explain why lock is there. Btw, same thing for mozilla
and thunderbird.

Sheng-Chieh

Firefox lock
 

I ran into the same situation, and fix, when I killed Firefox instead of shutting it down gracefully. Apparently removing the lock is part of the clean shutdown.

Dan:)