>>I've tried that and everything seems OK. The error doesn't happen everytime I quit the program, so it is hard to catch.
>
>While the form is loaded, in your view, do you add some records? Or, do you have something which may change the primary key?
>
>It might also be related to deleted records. I would pack the table in order to be sure we don't have deleted records which may contain the same primary key.

I'm going to close each one individually and see which one is causing the problem. Then go from there.

Ed