Then you are lucky
Maybe you have your refresh set at 60Hz?
Maybe you are using one of the X-geometries that doesn't get jaggies? (early in the thread I tried various geometries on my screen and found that some didn't cause any jaggy problem)
Maybe you are using X11 scaling and not XV scaling? (or was it vica-versa?)
Maybe we have different cards and the problem only occurs on some cards?
Lots of possibilities... all that I know is about 20 people or so have reported this problem in the course of the thread I originated and nVidia has failed to respond at all.