PC4000 problem???

I recently upgraded my CPU and memory and have been having problems when overclocking. Finally it seems that my OCZ PC-4000 2GB dual channel kit is at fault. The only way I have gotten it to run stable is setting the memory divider to 166 and running the memory at 200MHz or slower. I am running at the recommended 3-4-4-8 timings at 2.8v but I am also running at 2T instead of the 1T it says it can handle. When I run the memory above 205MHz it starts corrupting files and causing random problems. I have done the standard tests and made sure it isn't the CPU since even at stock CPU speeds the memory can't run over 205MHz or so. Advice or ideas welcome.

Thanks,
Keith

Opteron 170
MSI K8N Neo-4 Platinum
Memory Label: OCZ5002048ELGE-K
BFG 7800GT OC
Antec Truepower 2.0 430 watt
1x320GB and 2x250GB Hard Drives