Is this still an issue? The JIRA still shows as unresolved, but it hasn't been worked on in a while and losing messages seems like it might be a serious issue? Further to the dialogue between Tim Fox and Luca Padovan we are losing messages while depaging a core queue entirely on the server with no Client side, hence, no ack-batch-size complications. (It seemed to happen again with HornetQ-2.1.2-final stand-alone).
The term ack-batch-size is only referred to in the manual in the yellow box that Tim Fox refers to, so we assume that it can't be set on eg a server side bridge.
We are currently working on a work-around related to: