I honestly don't know, the system I did was installed with Win2k. I'm no longer putting win9x (95, 98, Me) as the primary OS on any systems.
You may be right, I'm basing my statements that the drivers don't work correctly in Win98 from second-hand accounts. You might want to try nVidia's own drivers, they are on their web site. I suppose if it doesn't work right, you are just a reformat and reinstall away from one of the later OSes. (If you have a win98 disk around.)