Access 2003 Error 3022?

I have created a database in Access 2003 with 2 tables, each with a corresponding forms. Suddenly, Access will not allow me to enter anything into one of my forms (the other form still "works"). No matter what field I type into, I get an error 3022 message. I have tried adding and removing a primary key, changing the one field that was indexed to non-indexed and indexed with duplicates allowed, and removing all relationships. Nothing has worked. Does anyone have any other suggestions? Could my file be corrupted?