mpeg streamclip and apple tv?

i've been exporting a lot of my HD created content using the apple tv setting in mpeg stream clip and this weekend i finally got an apple tv, but none of my videos work? i used just the standard itunes>apple tv 1280x720 preset. its set at 5000 by default and i've tried doing it at 3000, should i try a lesser amount?

also some movies i've apple tv'd out of handbrake don't work, using the apple tv setting. do i need to make modifications to that preset?

thanks!