245 spec voltage: 0.85-1.40V
with max temps 74c
Loosen the timings on your RAMs and see if you can do 265MHz or so -- hopefully the RAMs will take the OC.
Other than that you need to isolate
each component to determine its functional limits. I haven't had the pleasure of getting to know that motherboard but what are the limits? Can you go 13x290MHz?
That way you could drop the RAMs another notch (probably need to drop back the NB multi a notch, too, though 2900MHz has been done on the AthonII NB/IMC).