Sabertooth P67 vs GTX295

my system is :

Intel Core™ i7 Quad Processor i7-2600K 3,4GHz
ASUS Sabertooth P67
Corsair Vengeance™ DDR3 1600MHz 8GB CL9 Kit w/2x 4GB XMS3 modules
Nvidia evga Gtx295
NZXT TEMPEST Midi Tower Svart Fläktar: 2x 120mm Front, 1x 120mm Side, 2x 140mm T
Seagate Barracuda 7200.11 500GB
Corsair TX 650W PSU

Now to the problem
on boot i only get an black screen and then VGA_LED is RED on mobo
but the funny part is, if a change my gpu to an HD4850 all runs just perfect

things i have done to get it to work:
Gtx295 works fine in an other system
system works great if i put in my HD4850 card
change my psu to an Corsair HX 750W PSU same problem
checked mem one by one no change
reset cmo no change
use 2 pcie slot no change
change monitor no change

anyone got any suggestion, have RMA 1 mobo got a new today same old same old with this one..