I have a dual boot laptop with Win7 and Ubuntu 11.10. Since few days my Ubuntu does not mount automatically the win partition or a usb drive. It's also not possible to change the desktop wallpaper.
I "fixed" the win partition by hand modifying
/etc/fstab. I also played a bit and now Ubuntu mount the usb drive. On the other hand I cannot unmount them because
umount: only root can unmount UUID=521832F21832D4A7 from /media/WINDOWS
But my account is admin, so I do not understand why I have this message. If I unmount with sudo from terminal there is no problem. For the wallpaper I have no error message but I can't change anything. I also tried to assign my account to "normal" user group and then back to admin group: useless.
I believe that even if my account is administrator there is something messed up with permissions. Few days ago a guest played a bit with my account and the standard guest user (he couldn't unlock as he forgot the password). I don't know if this could be the cause, but at the moment I don't understand what it could be. Thank you for your help