What you need to do is insert your Office 2007 install disk, then go to add/remove components, then expand Outlook, expand outlook add ins, then make all of the add ins not available. This should take care of your problem.

According to microsoft, the most common cause of this problem is basically that add ins are trying to install at the same time as outlook. They say that this is caused by add ins that are from the OEM of your computer, but my office CD is directly from Microsoft, and I still had the same problem. As soon as I removed the "Microsoft" add ins, the problem went away. But then it is typical of Microsoft to not admit their own errors!