Bug#590213: bug only on NFS mount directory

[Marco Righi]

Firefox often shows the red sign (The bookmarks and history system will
not be functional ...).

The problem exist if the profile of firefox is loaded using a directory
mounted by NFS.

As wrote, the problem is not resolved using the followings:

- delete places.sqlite and places.sqlite-journal
- delete .mozilla directory

Thanks
MArco Righi