Has anyone found a solution to this? I just got the ATV for Christmas. I'm running ML on my 09 MBP, the latest software is installed on all devices. My router settings were followed from apple's troubleshooting suggestion, nothing. After resetting my router and resetting ATV twice, still nothing. Seems to be a known issue just by goggling it. Some have had luck by resetting their router and ATV but nothing for me.