Hi,
I enabled ssh on my AppleTV the I installed perian/A52Codec/ATVfiles... and now my AppleTv after few minutes of use reboot. Any suggestion?
Please help me

Ok... it's watchdog

How the remove/disable:
http://wiki.awkwardtv.org/wiki/Watchdog

and something from Turbo's site:

Disable ripstop
Purpose: Ripstop is part of the watchdog system that reboots if the default application doesn't run
Code:

mkdir /etc/mach_init.disabled mv /etc/mach_init.d/ripstop.plist /etc/mach_init.disabled

Notes: Make sure to make the startup script changes to disable the AppleTCOWatchdog kext or your machine will reboot. May no longer be necessary