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