Ignore the message below
Lockups still occur, they're just few and far between.
Ok, I've verified that the random lockups were just a "new card" issue. The console switch still locks up, but random X lockups are gone.
It was a power issue. Probably the Geforce4 uses more power than the Geforce2, and increasing the power to my CPU by a small amount rectified the issue. It was probably very margional before.