Who told you that it was a timing problem? Tech support? If so, I wouldn't trust them anymore than I would a bum on the street.
Test your memory, this will tell you if everything is fine with your system. Burn a copy of
Memtest86 (it's free) and test your memory with it. I would start by testing the BIOS default of 8-3-3 and then testing the RAM at 3-3-3. If your system passes the memory test, it is highly unlikely that your memory is to blame.
Are all of your games crashing or just certain ones?
Have you tried upgrading your video drivers?
Do you have the latest verison of
DirectX?
Do you have all the current drivers for your motherboard installed?
Are you pushing your system too hard?
Have you overclocked your system?