Even Office 2003 from Microsoft has failed to install on a clean Vista machine. Seems UAC needs some work.
I decided to restore my Vista notebook to the "out of the box" condition for a variety of reasons. I also decided to install SP1 while nothing else was installed. Well, it didn't take long for the first problem to occur. My PC Tools Spyware Doctor with anti-virus wouldn't update. I couldn't find a patch so I started over. If there was going to be a conflict, I'm glad it happened with the first program I installed.