Locate gives Record not found exception

We are in the process of upsizing a paradox database to Interbase.  We are
having problems with TTable Locate on detail Tables when performing a
locate on the non-linked field.  An exception Record not found is raised.
Locate should not raise an exception but should return false if a record
cannot be located.

We had this problem on Paradox tables with a corrupt index and was solved
by deleting the index and re-creating it.  We have done this with the
Interbase tables and done a database backup and restore, but the problem
still persists.
Roger Graham
DesignKey Ltd (UK)