Intuitively, I think this is what happens: sometimes when requesting a token, the connection is reset (or something equivalent) - this is why it only happens every now and then. This is then interpreted by the framework as 'hey, we cannot get the data right now, so let's assume something more-or-less sensible'.
Sound reasonable... But as we try to get a piece of productive software, honestly I do not feel good with terms like "Intuitively" and "reasonable"... ;) In my opinion the source of this (miss)behaviour should be tracked down. Thus I filed a bug report at sf.net:
https://sourceforge.net/tracker/?func=detail&aid=3397944&group_id=93...
Thanks again, greetings