Hi Elliot,
That's very interesting, I haven't heard of this issue yet. I'm almost certain that it will be fixed by a later release of Creo 2.0.
Here's a link that should have version M110 on it, which officially supports Windows 8.1.
https://support.ptc.com/appserver/auth/it/esd/academic.jsp
When Creo 2.0 M040 was created, Windows 8.1 wasn't out, so obviously it is not officially supported. Let me know if you are still experiencing issues!