And other games play ok ? It could very well be a securom problem. Go to the publisher/developer's forums for the game and demand they do something about it, after all it was their dumb idea to use securom
You might want to keep checking out cracks, some crack groups rip out all securom related code, so with those cracks you might have better luck. Have you tried a gimpsRus crack (those are usually pretty good, don't know if they did one for those games). And another thing, windows 98 is getting more and more unsupported, it's a very real possibility that future securom games won't work under win 98 anymore...