Mpeg 4 Video on Camcorder TV Out

Just purchased a Mustek DV Video Camcorder i spotted going on the cheap and figured I may as well take the first step into the world of photography and filming with this budgetish 4 Megapixel setup.

My impressions are it's a great piece of kit, especially for a first timer, however I did notice that the videos that are encoded by the camcorder appear to be Windows Media Mpeg 4... so putting my thinking cap on I decided to encode my own custom file (video) and stuck it in the same folder on the camera, and named it in sequence to my other videos (IMAG0004)
However no matter how hard I try the camera just won't have it.
When the camera turns on the file i've placed in the directory just doesn't show up. It'll say for example 3/3 files on the camera when there are 4 including my video.
Does anyone have any idea what the camera may be detecting that alerts it not to play or recognize the file? :(

try deleting oneof the existing files and replacing it with yours. might work