For the record, Cakewalk gets the award for the most problematic bunch of soft synths in my virtual instruments collection. Hand down and by a long, long, long shot.
Glitches, bugs, authorization issues (which could have ruined my ears), unexplainable issues like the one above...
Let me put it this way - working w/ Cakewalk products reminds me of all that routinely used to suck when I was working with Windows.
As such, the solution to the above issue was a typical PC solution - quit the session, re-download, re-install and re-authorize the plug-in.
Random things you can't quite explain go wrong for whatever reason, which you can't figure out because NOTHING has changed on your system, and you fix it w/ a totally generic solution - that's one of my most prevalent memories of working on a PC. In fact, I used to think that this was a normal part of working w/ computers.
But to be honest, I don't usually see such things on Mac OS. In fact, that stuff only seem to happen w/ Cakewalk synths. As amazing as they are otherwise, those products carry forth that tradition and port it to another platform... Kudos for that.
A true shame because the synths themselves are great. But I can't honestly recommend them.