I took a look at the Gravis site and you can find an answer about it using the following link:
http://38.200.209.141/support2/readlink.asp?query_id=246&osvalue=win98,
It is not too positive I am afraid: They are aware of the problem but did not fix it yet.
They are working on an update of Xperience and as long as it isn't there the only way of using Xperience is going back to directx 6, which means reinstalling Windows '98

Strange that Microsoft didn't provide a way to uninstall direct x 7. You get the feeling that Microsoft want to force you to use their software, else things don't work. It's getting worser and worser with them....

Han.