I searching for clues why my MDB is not running on all servers to which it is targetted
in my cluster. This MDB is subscribed to a topic. When a message is published
to that topic, only one MDB instance ever runs. It executes on the same server
where my JMS server is targetted. Suspicious, I moved my JMS server to another
server, and sure enough the MDB goes along with it. Meanwhile, no MDB ever runs
on any other server, although its targetted to all of them.

I've read about "distributed destinations" in 8.1, but that shouldn't be required
for the simplest pub/sub scenario.