One more thing to note...I went back and saw you do have the same sticks.

try these, I found after a bad OC attempt if I reset to these settings MemTest was fine.

Clock Mode: Linked
Ratio: Sync Mode
FSB (QDR): 1600
P1: Enabled
P2: Enabled
tCL: 7
tRCD: 7
tRP: 7
tRAS: 18
CMD: 2T
Voltage: 1.9v