I want to start with - I am a noob linux user.
I had the same problem today. Fresh squeeze install then shutdown for the night then updgraded to wheezy in the morning.
I installed from the 180 MB or sth CD. I choose alternative lxde desktop then graphic install. when squeeze was installed it was idleing till I turned it off for the night(I didn;t use it). The next morning I started it, opened LXTerminal, logged as su, used nano to change sources.list then upgraded.
The only thing I did before I opened for the first time libreoffice was adduser to sudo and browse the internet for four hours plus some cosmetic changes to the look of lxde. My ~/.config/libreoffice was root.root I did 'chown -R user.user ~/.config/libreoffice' and now it is fixed. It is rare unicorn bug maby :)
Because I am noob the only thing I can do is confirm that the bug exists.