Hey guys if you want to downgrade XBMC or go back to Frodo 12.3 from Gotham 13.1 follow these instructions.
I decided to go back to Frodo as some Repo's stopped working but the main reason for me was my ATV 2 was rebooting after 2 seconds of playing a HD movie.
ssh root@[Apple TV IP Address]
NOTE: You’ll now want to answer “yes” and then click enter if prompted, and use the password “alpine” (without quotations) with the username “root” as usual.
rm -f *xbmc*.deb
dpkg -i *xbmc*.deb
For more info or support on this please visit my good friends http://www.xctechs.ca