I found the error. File mssql-ds.xml in JBOSS_HOME\docs\examples\jca has the right SQL 2005 class specified but still the SQL 2000 connection-url. The SQL Server 2005 JDBC driver has a different URL prefix from the SQL Server 2000 JDBC driver. The SQL Server 2000 JDBC driver uses an URL prefix of "jdbc:microsoft:sqlserver://", while the SQL Server 2005 JDBC driver uses an URL prefix of "jdbc:sqlserver://". Maurizio View the original post : http://www.jboss.org/index.html?module=bb&op=viewtopic&p=4253435#... Reply to the post : http://www.jboss.org/index.html?module=bb&op=posting&mode=reply&a...