Had this problem on one of our seats.
I have to say that we were upgrading from a 2010 install with a few corrupt features (SW Explorer not working anymore, frequent bluescreens etc), most probably due to problems in previous updates. Guess the machine didn't had a clean install since 2005.
The problem was solved with a full uninstall, registry cleaning and reinstall from scratch using the source provided on website.
When ever I see issues like this I immediately think that a fresh install needs to be done.
There is probably a carry over from a previous version. Even though you didn't have the problem before.
Check out this thread.