Might seem stupid but try a LOWER voltage. Try going just above stock to see if it helps. too much voltage can hinder an OC...
MB Intelligence Tweaker:
Graphics booster: auto
CPU clock ratio: 9x
CPU Host Clock Control: Enabled
CPU host frequency: 355
PCI-e Frequency: 100
C.I.A.2: Disabled
Performance Enhance: Standard
System Memory Multi: 2.00
Memory Frequency: 710
System Voltage control: Manual
DDR2 Overvoltage Control: Normal
PCI-e Overvoltage Control: Normal
FSB Overvoltage Control: Normal
(G)MCH Overvoltage Control: Normal
CPU Voltage Control: 1.35