Well im pretty sur we have found your problem dude.
You definatley need more voltage
:p
Unless you got more voltage to that CPU u aint going any higher. Sorry i couldnt break the news to you any easier.
I think your next post should be 'how do i voltage mod a Msi KT3-Ultra-Aru'
Anyway thats is my definate opinion. Your problem is you CPU is hungrey and needs more juice, feed it!
:D