This is an XA level exception where MSSQL is telling you that the commit phase of the 2PC is failling with a -4 error code. http://java.sun.com/j2ee/1.4/docs/api/index.html Something looks like it is misconfigured with your SQL2000 instance, or in the driver itself. I know that there were specific things that you had to do with MSSQL2000 to enable XA to work properly. Also, there are some fairly strict requirements as to the isolation level that you must use with the JDBC driver for this to work. Gonna have to read some doc I am afraid :-) View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=3987288#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...