Distributed Remote/Network Transactions with MSDTC

[jmcilhinney]

This is probably not related to VB but it might be so I'll post it here. If it's not VB related then the DB gurus may have an answer anyway.

Background:
I'm creating an add-in for Microsoft Retail Management System. RMS provides a main and an optional offline database connection. In single terminal setups there will only be a main database and it will be on the local machine. In multi-terminal setups there will be a main central database and possibly a local offline database too.

Issue:
I'm using a System.Transactions.TransactionScope object in my VB.NET code to wrap all my database updates. This invokes the Distributed Transaction Coordinator. If the database is on the local system there's no issue. If the database is remote then there is. Originally I was getting an error message telling me that the DTC had disabled its support for remote/network transactions. I did the reading and dicovered the security implications and where and what settings I had to change to enable this support. After following the instructions I read my DTC options look like the attached image. Now I create my TransactionScope and SqlConnection, then when I open the connection I'm told that the transaction has already been implicitly or explicitly commited or aborted. It certainly wasn't explicit on my part!

This might have something specific to do with the .NET classes I'm using but I think that it's more likely a DTC issue. Anyone got any insight?