You know, that's interesting. It only seems to happen on my box when my father-in-law is browsing w/Firebird. Same thing, the mouse is still functional but X is locked.
Originally posted by Neutro
When it happens to me, the mouse pointer is still functionnal, but since I can't telnet / ssh to my machine to kill X, only alt-sysrq-S/U/B does the job for me. ctrl-alt-backspace to restart X doesn't start, ctrl-alt-Fn to change vc doesn't do anything.
For me, its seems to always be when Mozilla is open, although the folks at Mozilla's Bugzilla say this can't be Moz's fault.