When you edit data that uses multiple forms that have the same record source, you may receive the following error message:
This record has been changed by another user since you started editing it. If you save the record, you will overwrite the changes the other user made.
Copying the changes to the clipboard will let you look at the values the other user entered, and then paste your changes back in if you decide to make changes.
A bit field has by design the possiblity to have 3 states : NULL, 0 and 1.
Now ODBC Linked tables have problems with does records for which the value of a bit field is NULL.
Make sure that you have set the default value for bit fields to the value 0 or 1.
Once you have done this you have should execute a little query to update those bit to the value 0 or 1.
UPDATE [Table] SET [BitField]=1 WHERE [BitField] IS NULL