ODBC Connection iSeries Access ODBC Driver V7R1. Vendor program not receiving success code

I'm using Endicia Professional (shipping softward) and set it up to use an
ODBC connection to write records to a file on our iSeries V7R1 using
iSeries Access ODBC Driver.

The process is writing the record into the file. However, Endicia continues
to post back all orders that are currently sitting in the post back data.
I have configured the post back data option to post back immediately and
delete posted records.

The records are not being deleted, I've been told that it's because the
ODBC connection, more specifically, the driver isn't returning back
successful.

I changed Endicia to show diagnostic messages, after it does the insert, I
see a message saying Rows Affected: -1. I'm guessing that this is the
reason why it's not being marked as being posted.

I checked the ODBC connection and verified that the commit mode is *NONE.
So the record should just write without needing a commit command.

Anybody have experience in this? While we attempt to resolve this issue,
I'm just having them delete the post back data every once in awhile. As
the post back data grows, the longer it takes to process one label print.

This is cross posted with EndiciaCommunity.com I'm just hoping that
someone here may have come across this issue with the ODBC connection with
either this product or any other windows program trying to connect with
ODBC.

Just an FYI, I used Excel MQ Query, inserted the record. The message
returned was Rows Affected: 1. This is what I expect from the Endicia
Diagnostics Message.