When I say hard lock / freeze I mean I cannot kill X, I can't do anything, I must hit the reset button on my tower.
AKA kernel panic bsod crash freeze lock frozen
Video freezes on the last frame of gameplay, the audio loops 1 second of sound before the freeze, the network appears to keep working, but I cannot ssh remote in to restart, keyboard unresponsive.
Memory allocation / ownership bug ??
I always use another X session/linux user when playing games. I'm not sure if the lock up happens when using the same user/X session all the time. I do not use switchuser, I quit my previous X session by logging off. Running X on 1 virtual console - F7.
The lockup occurs if I have been developing using my default linux user/X session. Then I decide to take a break and play games, so logoff dev user, login as game user. When I start the game, once game play gets started, the lock up will happen either immediately, or within 10 minutes.
Avoid lock ups by doing the following before playing games. - basically a fglrx reboot -