I recently encountered the following error message in Microsoft Access 2003: After further investigation, as suggested by a thread on microsoft.public.access.forms, the problem appears to be related to duplicate columns in the form Record Source. However, the error is not limited to simple duplicate columns. In my case, the duplicate name was the result of a table join where the compound names were distinct (i.e. Table1.Col1 and Table2.Col1), but the simple column names were not, which resulted in the error. Perhaps I shouldn't be using joined tables as my Record Source... perhaps.