I've got the same problem...
I've seen this problem come up a couple of times a week on the forums, and I've never seen an answer for the people who experience it. I've got a GeForce 4, w/ the latest drivers etc. and I've still got those pesky black backgrounds. If anyone knows what the deal is with this, post reply. Maybe I missed the solution.
Oh, yeah, I'm running 98 SE.