Rollback transaction doesnt work when DataAdapter.Update() throws exception caused by RAISEERROR in a trigger

[Mark Vuksani]

Hi,

I have a trigger like this (simplified to illustrate the problem):

--------
CREATE TRIGGER Test ON [dbo].[TestTable]
FOR INSERT, UPDATE, DELETE
AS

RAISERROR( 'test trigger error !', 16, 1)
---------

And a C# code portion: (new record inserted in dsFormTest.TestTable)

---------
OdbcTransaction odbcTrans = null;

try {

if ( odbcConn.State != ConnectionState.Open ) odbcConn.Open();
odbcTrans = odbcConn.BeginTransaction();

odaTest.InsertCommand.Transaction = odbcTrans;
odaTest.Update( dsFormTest.TestTable );

odbcTrans.Commit();

}
catch( Exception xc ) {
if ( odbcTrans != null ) odbcTrans.Rollback();
MessageBox.Show( xc.ToString() );
}

odbcConn.Close();
----------

BUT, instead of rolling back transaction, the odbcTrans.Rollback() throws
new exception with message:

System.InvalidOperationException: RollbackTransaction requires an open and
available Connection. The connection's current state is Open, Fetching.

any clues why?