by morgano » Jan 8th, '15, 19:53
Sorry your post have been unanswered for so long.
I have not used gnome for years, so my hints below are only general for complete settings reset.
If you still have problems, ask again and probably some with more gnome experience can fill in.
Of course, also search the web for gnome-tweak background if you have not already...
1) If you have not updated the system, do so in order to reduce the number of obscure bugs...
2) Clear the gnome settings. There is probably a hidden folder with gnome settings (search the web) Log out the affected user and rename that folder. (you may first want to create another user you can log in as)
3) Upon login the settings will be recreated from defaults.
At home & work Mandriva since 2006, Mageia 2011. Thinkpad T40, T43, T60, T400, T510, Dell M4400, M6300, Acer Aspire 7. Workstation using LVM, LUKS, VirtualBox, BOINC