Firefox locked for one user -- How to clear?

[Denis Melnikov]

I faced this problem when a user being logged twice, at a server and
at a client. Closing Firefox on the server solved the problem.
Isn't it your case?

Denis

> About once a week, a student approaches me and says that Firefox is
> broken. When you try to run Firefox, a message comes up that says that
> it's already running.  Re-logging in does not help. The end-of-day
> reboot does! This was a problem in Edubuntu thin client 6.10 and now
> in 7.04.