Sorry for the other posters, jema. Some tend to overreact and stray off topic too fast and too often.
You'll have to ask LucasArts support if they have received many inquiries on this common problem and if they have a solution. As for my statements I stand behind them as the truth to the best of my knowledge. Just because Microsoft released DirectX 8.0 with promise of better performance doesn't mean it delivers, LOL. DirectX 8.0 IS buggy and uncompatible with many games and system configurations. You can research this yourself. And you are right, there is no official DirectX uninstaller but you can find ones available from third party vendors. Or maybe get the latest version, I think 8.0a or greater is available now. Good luck.
Gold Squadron. The brightest star of the Rebellion Fleet!