The FD limit is an interesting thought; it hadn't occurred to me. I will try raising it. If that doesn't work, I will try the database login module, and then moving the application to a different server. Do either of you by any chance know under what circumstances JBM returns XA_RETRY on prepare to the TM? Your help is much appreciated. Many thanks. View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4164271#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...