I have successfully jailbroken my ATV2 using Seas0npass 0.70 and installed XBMC. But when I switch the power off to the ATV2, I cannot get it too boot up again. The white light in front just keeps blinking. I had the same problem after jailbreaking using Seas0npass 0.69 and Greenp0ison RC6.1. This is very frustrating as the jailbreaking process seems to work. I cannot even do a tethered boot as Seas0npass says it's not needed as it is a untethered jailbreak.
Any help is greatly appreciated !