I have a KDS AV-7TF monitor with a Hercules 3D Prophet II Geforce2 Pro video card. I messed around with some drivers, but ended going back to the Detonator 6.31. Now for some reason, the only two refresh rate options I have are optimal and adapter default. I used to use 85 Hz, but it seems that my computer has automatically defaulted to something lower, and I can't change it. What's going on?