Problem with SQL adapter

I’m
experiencing problems with the BizTalk SQL adapter. I’m trying to
create the corresponding XML schemes to execute a stored procedure,
which returns some data from a Microsoft SQL database by using the SQL
Transport Scheme Generation Wizard.

When specifying which stored
procedure to use, and clicking Next, I get this error message: “Failed
to execute sql statement. Please ensure that the supplied syntax is
correct. New transaction cannot enlist in the specified transaction
coordinator.”.

The DB connection succeeds, so that’s not the problem.

The stored procedure looks like this:
CREATE PROCEDURE [dbo].[sp_GetBizTalkMapping]
AS
SELECT [Map]
FROM [dbo].[Mapping]
FOR XML AUTO, ELEMENTS, XMLDATA;

I’ve tried removing the last line and I’ve tried using all combinations of these three parameters.

The table structure looks like this:
Method    char(100), Primay Key
Map        char(100)

I’ve found this article describing the same error message, but it doesn’t seem to be the same issue:
http://support.microsoft.com/kb/917847
The user logged in is dbo and I’m not using any of the specified datatypes.

Does anyone have a clue to what I’m doing wrong?

Btw. I’m using BizTalk 2006 R2