Got the same issue. Tried to up the NB clock but at 2400 it's unstable. Anything above 2400 won't even boot . Tried applying +.250 on both NB vid and CPU NB vid, but it seems like it doesn't apply the increased voltage.
Now i'm sitting at 2310 mhz for the NB and 1400 mhz with 6-6-6-19 for ram.
Is there any other way (except a DMM - my sister appears to have lost it ) to know if the increased voltages are applied?