Hi rachetta,
Maybe, then there is a stability issue with your OS X setup or the Office installation itself.
Have you tried running Office under a 'Safe Boot' to see whether the problem persists? If it doesn't, the implication is that the problem is caused by a background program or service. If it does, you may need to repair your OS and/or reinstall Office. For reinstalling Office, see:
http://support.microsoft.com/kb/2025907