[MPlayer-users] Strange X bug

[Adam Nielsen]

> all other X windows lost their titlebar, and nothing seems to respond.

If every window loses its title bar (including mplayer) then your window 
manager has crashed.  It's unlikely to be a problem with mplayer, but mplayer 
could be doing something unusual causing it to crash.  If you don't get any 
other suggestions, you could always try upgrading Gnome.

Cheers,
Adam.