So I had some time to try somethings.

Updates are up-to-date except iTunes.

I reseated the RAM so the 1gb dimm is in slot 0 and the 512mb is in slot 1.

The backlit keyboard function is off.

Deleted display preferences at Home > Library > Preferences > com.apple.systempreferences.plist

I tried to run ONYX but it froze before it finished.

I'm repairing permissions but it froze.

So it still freezes. I installed Temperature monitor and got some specs are these too high?

Battery temp 30°c/86°f

Power supply bottom side 55.5°c/131.9°f

Processor bottom side 60.2°c/140.4°f

Processor/Controller Bottomside 47.8°c/118.0°f

Smart Disk 33°c/91°f

Trackpad 33°c/91°f