Easy fix :)

Author: hazzik

src/NHibernate/Transaction/AdoNetWithDistributedTransactionFactory.cs

@@ -29,7 +29,9 @@ public void EnlistInDistributedTransactionIfNeeded(ISessionImplementor session)
 
 			if (System.Transactions.Transaction.Current == null)
 				return;
-			
+
+			session.Connection.EnlistTransaction(System.Transactions.Transaction.Current);
+
 			var transactionContext = new DistributedTransactionContext(session,
 																	   System.Transactions.Transaction.Current);
 			session.TransactionContext = transactionContext;