Access violation - probably not the fault of Postgres

I've got an application written in VB which pipes updates to a database
in Postgres. The application is written in MS Visual Basic 6.0 using
DAO3.6 via ODBC.

If a record exists in the PG database and my VB app therefore does an
Edit/Update, it works without a problem.

If the record doesn't exist and I therefore need to do an AddNew/Update
my client application crashes with an access violation on the update.

I'm relatively sure it's something on the VB side that is causing this
and nothing to do with PG, but I'm just posting here in case anyone has
some thoughts about potential causes within PG or its ODBC driver.

Any thoughts would be welcome.

Thanks,
Paul.

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Paul Lambert
Database Administrator
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