i have the first 3 slots filled. when i remove the stick from slot 2, the pc won't get past the boot up screen. In slot 1 and 3 i have crucial ballistix pc 8500 and in slot 2 i have a ocz pc 8500. They're all the same speed and everything. I did remove the ocz one earlier and it all worked fine but my pc was still up to the same tricks eg having good fps untill i reboot then not again unless i cut the power. This is 1 annoying problem.