Vicky, thanks very much for your detective work, and for confirming the issue. Regarding your last post, I can only guess that JBoss 3.2.x shipped with an earlier version of hsql, and that version apparently does not have a table named INFORMATION_SCHEMA.SYSTEM_TABLES. You should be able to substitute any other available table for which you can isolate a single row; as you can see from the query, the results are immaterial. I'll look for a substitute table later today or tomorrow. Unfortunately, the workaround I proposed in the read.me of introducing a dummy hsql no-tx-datasource works for me in my Windows development environment but not in our Linux production environment. Don't know why, but for the time being I'm setting our Oracle datasource to use idle-timeout-minutes = 0. This prevents the IdleRemover thread from being created. Not an optimal solution, but will have to do until your fix makes its way into the code base. View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4163950#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...