Strange Access and PgSQL ODBC

 A while ago I posted a message about stange deletions in a linked table.  When a value would be entered into the table through access (table or form view), it would change all the values on that row to #Deleted, until the table was closed and reopend.  I figured out how to repeat it but still have no idea how to fix it.  Whenever I eneter a value that is already in the table it does this.  If you have a field called firstName and Chuck is already in there, enetering Chuck again will cause this.  If anyone can help I would really appreciate it.

Thanks 
Charles Killmer