Every time I try to use LibreOffice appears:

The application “LibreOffice” unexpectedly quit while trying to restore its windows. Do you want to try to restore its windows again? then it has two buttons Don’t restore windows and Restore windows.

Neither button does anything and the nag screen stays there. A forced quit doesn’t help. Ideas? I am on a MacBook Pro with Mac OS X 10.7.3

Please have a look at → Restore Windows