I'm getting the "The video could not be loaded, either because the server or network failed or because the format is not supported" on my iPod Touch. All seems well with desktop web browsers and Android.
Here are the specs on the video format of the mp4 files.
Audio: AAC, 44100 KHz, 121311 Kbps, 2 Channels
Video: AVC, 480 x 270, 495 Kbps, 29.97 fps