Currently I have an ECS K7S5A (latest revision) with a Duron 1.2GHz and 512MB of PC133 (2 sticks of 256). I just got 2 256MB Crucial PC2100 DDR. When I installed the DDR, the computer refuses to boot. The fans spin, but there are no beeps. I put the PC133 back in and it works perfectly. I tried reinstalling the DDR RAM multiple times, but with no success. I have tested the DDR RAM in another system and it works as well. Has anyone seen a problem like this before?