I done a downgrade to 4.0 with no problem following your howto. Installed the package (I need to unpluged and replug the power cord to reset the atv2 after that to get back to main menu).
I also installed ninoTV that implement a working afpfs-ng package to mount afp share from network.
Is there a way to permanently mount a afp share (and where to mount it) in the atv2 to get media from it ?
If not, I will get back to 4.2 and will wait a release including that fonctionality as the airplay is a very interesting feature (I put my kids moovies on her iPod).
Great work anyway, the implemented functions works well.
Does anyone know any NAS with a flex server (I have one that does iTune Media server with realtime transcoding from now but it only read few format)?