FSX graphics card error. "does not meet minimum re

I'm suddenly getting this error with fsx sp1 (and expansion pack):
"This graphics card does not meet minimum
requirements for shader support. This product requires a geForce3/Radeon8500
class or better graphics card. Flight Simulator will now exit."
As far as i can tell... the reason why this may be occurring is because
i've added a second video card to my system (geforce 7600)... my primary is
an 8600
Any thoughts?
Anyone running two video cards and able to run the simulator?
Thanks
"This graphics card does not meet minimum
requirements for shader support. This product requires a geForce3/Radeon8500
class or better graphics card. Flight Simulator will now exit."
As far as i can tell... the reason why this may be occurring is because
i've added a second video card to my system (geforce 7600)... my primary is
an 8600
Any thoughts?
Anyone running two video cards and able to run the simulator?
Thanks