I'VE FIGURED IT OUT!!!!
Remember all those problems I've been having with CTDs with 3D games (Raven Shield, Hitman 2, Splinter Cell, etc.)? Well, conventional wisdom and advice told me to upgrade the drivers. However, what I should've done (and ended up doing out of desperation) was to downgrade from the 40 series of Nvidia drivers to the 30 series. My thinking is this: I own a GeForce 3 and I think the 40 series is optimized for the GeForce 4.