HELP!!! Display only works in VGA mode

[tracethis]

Hello All:

My problem in a nutshell is that I don't get a display on my PC unless I enable VGA mode at startup. First, here are the specs of my PC:

Amptron motherboard w/ SiS730S chipset (onboard audio, LAN & video)
AMD Athlon 1.2GHz
256 MB RAM
3DFX Voodoo3 AGP card
Compaq Presario 1725 monitor
Running Windows XP Home Ed + SP2

Here's a little background on the PC. I bought it used w/ win98se running on it. The display seemed fine under win98se. I clean installed winxp and from that point forward, I haven't been able to get a display unless I enable VGA mode when I boot. I ran win update and it picked up hardware updates for the 3dfx voodoo3 and my motherboard, but still no display.

When I boot in VGA mode and try to change the display settings, the display fails. If I try to change the monitor type from "Generic Television" to "Plug and Play Monitor", the display fails. Basically, any change that I try to make to display settings results in the display failing.

I downloaded and installed the "AmigaSport 3.0 XP" full version drivers, closely followed the installation procedure and still I have the same display problems. I downloaded and installed the latest 3dfx voodoo3 drivers (v1.07) from falconfly.de, still nothing.

Am I missing something??? Is my 3dfx voodoo3 toast? If so, why did the display seem fine under win98se 2 days ago? Is there a special rite of dance that I need to perform to bring my display to life?

Any advice, help, information, etc, is welcome and greatly appreciated.

-Thanx