>Brandon - do you by chance use the nBit control? People are just now reporting problems on Vista PCs that have IE8. But it works on Vista machines with IE7. Details on Vista / IE version requirements are sparse on their website and they have yet to reply to an email i sent. I am getting "class not registered" messages (but the control is registered) on the IE8 machines

I have IE8 on my Vista 32bit dev machine and I just tested the nBit control and it worked fine?

Are these customers using Vista 64 bit? If so you may have to make a DEP exception for you application.

http://forums.auctionflex.com/viewtopic.php?f=5&t=7