Hm ?

So you are using custom Mouse Pointers for your Windows, but the Actual Pointer shows completely screwed up ?

There are not many reasons I can come up with.

First, no 3dfx Driver had ever such a problem, so what you're having is not inherently Driver related for sure, although it might have a influence.

Tip 1 :
Use default Mouse Pointer under Windows.

Tip 2 :
Check Bios setting for Items like "Palette Snoop" (Disable), "Video RAM Cacheable" (try Disable), "Video RAM Cache UC/USWC" (try UC)...
Far shot, but it might be...

Tip 3 :
It is more than a bad workaround, but try reducing "Video Hardware Accelleration" step by step, just to see if the Problem ceases...

Tip 4 :
In case this happens in Games only, look for a setting "Hardware / Software Pointer".
In a few games, some DirectX Drivers appear to have troubles with running a custom Mouse Pointer in Hardware, that's  where a Software Mode can help. That should work in most cases...

Other than that, there's nothing that I could directly come up with

Greetings
FalconFly

Yep, good idea

If the problem persists with a "Standard VGA" Driver, it's most likely either Hardware or Mouse Driver related...