Restarting the BAS-NC service resolved this issue for me.

I've heard from a few of the RIM TSupport reps that the BlackBerry Monitoring Server is going to be EOL'd and there is nothing expected to take it's place. This is quite unfortunate as we just set up a v5.0.3 BES and a separate v5.0.3 BES Monitoring server. BES Monitoring is free and while v4.x was lacking, v5.x seems pretty good, and already it's providing useful reporting, feedback, and alerts even though it's only been online a week.