As the Apple TV doesn’t let you connect a drive directly with your content (it requires a ‘middle man’ of iTunes) getting your content to show up can be a little trying at times. Some of the reasons why it goes wrong are:
- The Mac serving the content isn’t on
- The Mac serving the content has dropped off the wifi network (happening a lot in Lion)
- The Mac serving the content doesn’t have iTunes open
- The Mac serving the content has iTunes open, but Home Sharing isn’t turned on (or using the same login as the one specified on Apple TV)
- The drive where all the content is stored has become unmounted, so iTunes can’t access it
- You’ve remounted the drive, but there’s a bug where if iTunes has tried to play content stored on the network drive, it corrupts the file path data, replacing it with some other obscure file (in my case, it seems to be a photo folder bizarrely)
In short, there’s too much to go wrong, and Apple TV is on the naughty step until these steps can be bypassed without hacks. Rant over.