Problem? What Problem?
Well I couldn't push it past 64C per core - is that good or bad?
I believe I have fixed it though - I was using both the 8 & 6 pin plugs on the same cable - as soon as i used a second cable it was fine & also scored an extra 1000 in vantage.
I thought it didn't matter if 1 rail was used or 2, so long as your psu had more than 46amp in total (12v) - oh well