Hey.
My problem is that whenever I'm playing for about 10 minutes or so, the game will just stop, my mouse and keyboard will disable themselves mostly and I can't do much until it goes back to normal which can take quite a lot of time.
It also finds a way of minimizing the screen and moving it always to the top left-hand side corner of my screen.
The only way I've worked out how to stop this everytime it works is press the power button on my laptop and get my power-off menu up, use the arrows to go down to cancel, press enter when cancel is highlighted and then it should return with a couple seconds thereafter.
I'm using Ubuntu 8.10, I have enough RAM and large enough CPU for the game as I've already checked this too.