E6600 system no longer stable at any overclock

[genec57]

E6600
eVGA 680i mobo
4 1gb Corsair XMS
7900gs Nvidea

System was overclocked to 3600 with vcore of 1.45, unlinked memory voltage at 2.0
It ran stable with dual prime 95 for 1.5 hours. I then found out about p23beta2 bios from evga and installed it.
Since then the system is unstable at all oc settings. Core temp showed nothing over the mic fifties at any time. I took it back to P 21 bios and the problems remain.
It is presently stable at stock settings.
Any suggestions will be sincerely appreciated.

 

[dermotti]

I assume you cleared the bios with the jumper to clean out any rogue settings?

 

[genec57]

I did indeed.
After a stable stint at 3200 (30 minutes ortho) I am now back to 3400. so far, it is stable after 15 minutes of ortho.
It would appear that it just needed time to stabilize after the bios nonsense
(fingers and toes crossed) .
I know better - don't mess around with beta unless there is a very good reason for it.