To answer some of your questions, using your numbering scheme: 1) There is just one thread. 2) It's been resolved with respect to JBossTS. That is, the assumption about ordering is still there, but the specific problem with JBossTS that made that assumption incorrect is fixed. What transaction manager are you using? 3) Will reply later. 4) I suspect the problem lies in this area. If putForExternalRead() is being called when there is already data present, it will *by design* result in nothing happening. The design intent is that whatever is there is the same as or newer than what the putForExternalRead() is attempting to cache. If that's not the case, something is wrong -- either the call shouldn't be a putForExternalRead or a call to clear out the old data should have happened and didn't. View the original post : http://www.jboss.org/index.html?module=bb&op=viewtopic&p=4214597#... Reply to the post : http://www.jboss.org/index.html?module=bb&op=posting&mode=reply&a...