I have fixed a few issues in regard to that.
Do you think you could give a try on Branch_2_2_EAP or Branch_2_2_AS? They are the same now.
We will try and test again on the new version, but first we need to be sure how reliably that we can see this behaviour on 2.2.5-final.
As it stands it failed once with 500,000 messages (~4k each) on each of two subscriptions over two attempts, and once with 1,000,000 messages (one attempt), but works reliably with 10,000 messages over 5 attempts (and it takes us some time to generate each message as we're pulling them over a JMS bridge in the first place).