To preface: I know that the newly supported Airplay mirroring from iMac/MBP to AppleTV is only supported on newer models... This is not my problem - although I am very disappointed with that too. My problem is that up until my install of Mountain Lion, I have watched movies, streamed music, etc. from iTunes to my ATV3. Now it is broken. iTunes and ATV3 are talking with each other since my Mountain Lion installation... Any thoughts or ideas? Sometimes it starts, but then stops, and says it can't connect. :? Thank you!