Gamut's been lately giving some people a hard time about not being authorized to play games, or (worse) authorized to continue a game that they started earlier! This was due to a passel of bugs introduced with the latest version of the network's core "bookkeeper" module. We've been smashing them one by one, and I'm fairly sure that they're mostly gone now.
One known bug causes Gamut to sometimes give you this message due to a failed race condition in our protocol. The next release of Gamut will address this. In the meantime, if you see this message as a result of clicking the "Ready" button, just click it again. It should work.
Several of you are keeping us informed of when things go wrong, and this helps us tremendously. You are excellent betatesters!