I still have a Radeon64 ViVo in an older rig. ATI cards do, do funky things if you don't install them correctly. But it seems like you did.
If it only boots up in Safe Mode, go to Control Panel then Display then check to see what is listed as an adapter (video card) and your monitor... Also check to see how many colors you are displaying...
If it says something like:
Unknown on Unknown or,
ATI 9200 on Unknown or,
VGA on Unknown...
and you are displaying only, say 16 colors- you have got a problem...
Go to ATI.com and look around for support and the latest Catalyst drivers for Win98...
I would:
1) Download latest drivers for card (ATI9200/win98)
2) Get instructions from ATI about proper installation... Check to see if there are ANY problems installing this card in Win98 with any type of creative soundcard... They maybe sharing IRQs...
3) Uninstall present card and software.
4) Reinstall the card (yes, take it out on #3 and put it back in) and install the newest software.
5) Install any media software that ATI recommends or DX9...
6) Hopefully should it should work...
If not, check back here, with ATI, or at:
Rage 3D
Hope this helps.