I do not have an advanced account, so can't upgrade.
However, I do have additional info on the issue:
I cannot set an event for 13-12-2011, for the error of date in past (though it's not).
I can set an event for 2012, that's without any problems.
However, if I try to edit the event then, to one in December 2011, I can do that without any errors, but the date shown is: 01/01/70
That's wrong on just so many levels...
Any ideas on the problem? My integrations are up2date, I use CB Groupjive 2.3