If you are having problems with Office 2008 applications crashing on your Mac, it could be caused by Spaces. I didn't know this when I installed Office 2008, but it looks like it is not compatible with using Spaces and this is a known issue that neither Apple or Microsoft seem very anxious to solve. The only known way to keep the crashes from happening is to turn Spaces off when you are using Office 2008 applications. A pretty terrible solution. But better than having an app crash and losing work as a result.