That's odd... I'm running a GeForce 4 Ti 4600, and I'm fine.
Try updating your drivers.
Also, look at the sticky threads at the top of the forum - I think there is one on cards that definitely work, and what you may be running into.
What you're describing sounds a lot like what people with non-T&L cards experience. Mostly happens with laptops and old cards. But a GeForce 4 should handle it fine.