couple of other points you need to know if you're going to work in this area:
* alejandro recently reported in a forum thread that exclusive messages are processed sequentially by 1 MDB. we need to verify that each job runs in its own transaction. (maybe that is what you are actually reporting related to "ExecuteJobsCommand that much easier than the ExecuteJobCommand")
* i forgot the other point :-)
Yeah, thanks! I already saw that (in JIRA and code)...