I use a XFX 650i Ultra motherboard and I cannot use both ram modules together. I have tried "underclocking" both modules however Windows Vista will not boot up (blue screen of death). However if I use one or the other it works perfectly.
To be more specific:
OCZ 2GB PC2-6400 EL Platinum XTC Edition Rev. 2 Dual Channel DDR2 Kit (2 x 1GB)
and
Corsair 2GB XMS2-6400 Dominator TWIN2X Dual Channel DDR2 Kit (2 x 1GB).
To be more specific:
OCZ 2GB PC2-6400 EL Platinum XTC Edition Rev. 2 Dual Channel DDR2 Kit (2 x 1GB)
and
Corsair 2GB XMS2-6400 Dominator TWIN2X Dual Channel DDR2 Kit (2 x 1GB).