Here's an aritcle from the Microsoft Knowledge Base that might help. Perhaps you have the registry issue that this article describes... Then again, maybe not. In any case, if you do mess around with the registry, be very careful and precise about what you're doing, and, and do make a backup as the article suggests. You can serverely damage your operating system if you're not precise about making registry changes.
Aritcal 291473 from Microsotft Knowledge Base
Mike L.

