Screensaver freeze computer

I run OpenSUSE 10.3 on a Acer TM4000 with ATI Mobility Radeon 9700 64MB.
Until now i had no problem and was using SUSE own ATI-driver called “R350 NP”. This driver is 2D-only and does not support 3D acceleration.

Now i wanted to try Doom3 for Linux and installed it. Of course it want work and ID Software says ATIs own driver must be used.
So i downloaded og install ATI own driver, but it seems not to work. Then i entered and follows the instruction to install ATI driver. It installed and now i have some sort of ATI 9600/9700 driver with 3D-support, but if i now try to start Doom3, then the whole computer freezes. And even if screensaver enable, then it also freeze the computer. I guess there is something with 3D or OpenGL that is not working.

Now i want to scratch the computer and install OpenSUSE11. I’m try to take backup of my files, but i cant leave the computer because screensaver freeze computer. If i enter Screensaver configuration to disable screensaver, it also freeze computer. I guess preview screensaver is enough to freeze computer.

So how do i disable screensaver in terminal?