I must admit to us having known about this defect for a while. It is as you have noticed related to the Commons Configuration usage, and as such is linked to the xml config files rather than an inherant limitation of the broker. Although I can't admit to having tried it (our users dont tend to use dots so it has never become a priority) the JMX/HTTP interfaces shouldnt present any such restriction (but obviously cant currently create virtualhosts...though it is coming).
We will take a look at the patch later in the week probably (a bit swamped at the moment, hence the 11pm reply) and apply it if all seems well. It's probably worth me mentioning that we are currently undertaking a long term project to rework the broker management and configuration, including removal of the XML configuration hopefully for 0.20, so this was getting resolved one way or the other, but thank you for the patch in the meantime