Christina...I went out on the net just to see if anything jumped out at me. It could be that your Outlook has a corrupted file and will need a re-install but that's worse case scenario. Try this link, if you haven't found this site already, and see if this helps...
http://www.msoutlook.info/question/280
I'm sure you've gone out to MS and checked their site for troubleshooting tips. If this is a new purchase you should have some support. If you post the question on a "techie" forum, you might get a useable response quicker...if I run across anything else, will let you know.