There are quite a few things which can contribute to this issue. Typically it is driver related. For example, we know the 61.77 driver from NVidia works better with all NVidia video cards from the FX5xxx series and back. The use of a later driver will cause lock-ups, stutters, and a melee of other troubles.

The problem can also stem from having "fast-writes" enabled in your computer system's BIOS ROM for the AGP bus. Particulary if you are using a motherboard which is based on the VIA chipset.

Out of date motherboard drivers (INF files) can also cause this problem.

It could be due to the computer having a multi-core CPU.

If you are unable to correct the problem. You can send us the output from a DXDIAG (Start->Run->DXDIAG) to support@hitechcreations.com and we will be happy to take a look.