The value in sqlerrtext has no real meaning until you actually attempt to use it in some fashion. Checking it after assigning the dbms attribute serves no real purpose and I'm guessing that the value you see is an artifact (or default) and serves as a reminder in case you do actually use it in some fashion before establishing a connection.
Now, if of_connect fails then you should check sqlerrtext for (hopefully) useful information about why the connection failed.
Lastly, as Lars points out, you should be careful about using a local variable for a transaction object as this can leak connections.