Scott- You had posted this over on Handbrake, and I am the user (Da Man) that hijacked your thread like German east-block terrorists going after Nakatomi Plaza on Christmas Eve. Let me see if I can help you out with a few tips-
-As stated over at Handbrake, ALL Disney movies need to be pre-ripped using Mac the Ripper or Ripit, and even then should be "washed" with DVD2oneX using the movie only mode. The combination of these two should strip any content protection as well as any intentional "mastering erors".
-Just because it will play in iTunes doesn't mean it will play at all on AppleTV. The way to confirm AppleTV isn't accepting it (as opposed to it being an AppleTV glitch) is to click on AppleTV under devices, click on the movie tab, and click on the box that allows you to synch one movie only, and select that movie. Then hit apply, and synch, and see what happens. It should finally give you a little asterisk when you're done next to AppleTV under devices. Click on the asterisk and it should say something like "AppleTV is unable to synch this movie because AppleTV cannot play this movie. Yes I know, very informative, but it's a start. Put your AppleTV synch/stream settings back where how you originally had them set.
-Run the .M4V file of Mulan in quicktime and activate movie inspector. Take note of the various bits of information movie inspector tells you. This is going to be the best way to figure out what's up here. A screenshot posted here would be great if you know how. Use your Apple's help menu, type in screenshot, and it will give you directions on how to do that.
-Looking at movie inspector, see what the frames per second are, resolution, and bit rate. There are very few reasons AppleTV will reject a valid .m4v file. It is named .M4V, right?
Post back here with this information and we'll go from there. However, if you're not using a ripping program (handbrake is NOT a ripper) this is the first thing to try.
Good luck. And like Riggs said to Murtough in Lethal Weapon 3 while he was sitting on the bomb-laden toilet, "hold my hand and we'll get through this".
