System lockup after installing new 3D card

[cal]

I have a p11 400 @450 bx6 2 running win98
I've just installed asus riva tnt 3D card. when I change the color settings to any thing more than 16 colors and restart it locks up when it starts loading the desk top.
I've uninstalled and reinstalled the driver twice with no luck.
Anyone got any ideas.
Thanks

[DavidX]

Look at the properties of the video card in Device Manager. See if it has been assigned an IRQ and if that IRQ conflicts with any others.

[RobRich]

Have you tried changing video drivers to a different set. Get the latest reference drivers from nVidia or look for an update to yours.

[R.I.P.]

Have you tried setting your bus speed back down to orginial spec to see if it is stable??