Transactions and Errors with ODBC

I've just joined this list, after scanning through the recent archives, to ask
this question. I have been unable to control transactions and locks through
an ODBC connection. I have also been unable to obtain meaningful error
values. Now, my problem may very well be with the interface I'm using,
Passport 4GL, which few if any of you have probably heard of. I'm using
postdrv 6.5 from Insight Distribution Systems on an NT 4.0. My server is
RH6.2 with PostgreSQL 7.0.2. I have not had any difficulty with "normal"
database interaction; ie select/add/update/delete.

In regards to transactions: I have been unable to lock a row for update nor
has rollback worked. These do function normally with psql and with PG Access
on the server.

In regards to error messages: The value returned to my program is always 1.
I've been testing by trying to insert and update a duplicate value in a unique
field. The insert and update does error as it should but I would also like to
provide the user with a meaningful message as to why.

Are these known conditions with ODBC or do I need to deal with my interface
package?

Thanks,
Scott