I have a Late-2011 13" MBP that came with Lion, and I just upgraded it to Mountain Lion last night. However, since the upgrade, it no longer works with my Time Machine backup I've been using on Lion. When I try to backup, it pops up this box: Does Time Machine not support backing up to the same disk a previous version of OS X (in this case, Lion) was using? Do I have to wipe the whole backup and start fresh? Or is there something going wrong here?