DBM_INIT distributed transaction rollback in profiler

SQL Server 2008 R2. WebSphere 7.x Windows 2008 server.

Our application is JEE in WebSphere 7.x, and so uses Microsoft JDBC I believe 4.0 to connect to the db server.

During one of our batch jobs, I'm seeing a series of 20 rollbacks on a transaction that appears to be named DBM_INIT. Specifically: EventClass = SQLTransaction ApplicationName = Microsoft JDBC Driver for SQL Server EventSubClass = 2 - Rollback HostName = our app server LoginName = our login ObjectName = DBM_INIT

In every case the EventSubClass 2 is paired with a 0 - Begin just before it, and nothing in between.

Another forum speculates that it's a named transaction. I cannot find this transaction in our application. Google doesn't hit anything useful, either.

The "Application Name" in the profiler trace is "Microsoft JDBC Driver for SQL Server". Given that and the fact that I cannot find it in our application, I'm left to speculate it's something to do with WebSphere db connection pooling. Maybe it's doing something when it forges a new connection for the pool that leads to this?

I was wondering if anyone has encountered this, or might be able to tell me, more definitively, what this might be?

It's really bothering me that I don't know what this is :-(

Thanks in advance :)