It's a beta. Be glad that pre-orders get to play it at all, normally you would have to wait until January. You also consciously checked 'show pre-release versions' in SDC, what did you expect? A perfectly complete, bug-free version? It wouldn't be Beta then.
Furthermore, there is a new Beta coming out WEEKLY. Other companies give out a (public) beta ONCE, and that's it. If they have open Betas at all. Seeing posts like this, I understand why they don't.
On the issue itself: There seem to be several threads about this problem, if it hasn't been fixed in the last Beta already.