Trouble Opening Office Documents

I’m running Windows XP and Office 2003 Student/Teacher edition. Lately I am unable to open Office documents from either Windows Explorer or from the My Recent Documents file. I’ve checked the program associations and all are correct (.doc files are associated with Word, .xls files are associated with Excel, etc.) When I click on the document’s icon in the My Recent Documents listing, for example, nothing happens at all. There’s no error message, just….nothing. Not sure why this came about recently as I haven’t made any system changes. I reinstalled Office, to no avail. Any advice? Thanks!