This isn't going to solve your problem, but first, in the cache config file, make sure SyncReplTimeout is at least of few seconds longer than LockAcquisitionTimeout. If you do that, and you get the same exception (look at the details of the error message; it's important) then you need to start by debugging the connectivity between the servers. See http://wiki.jboss.org/wiki/Wiki.jsp?page=TestingJBoss[/url] and [url]http://www.jgroups.org/javagroupsnew/docs/newuser/node6.html. If you get an exception that talks about failure to acquire a lock, then make sure sticky sessions are working correctly. View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4039400#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...