My MP4 Watch can't play video
 

Hello all!
I've already read nearly all threads on this forum, but nothing helped me :( Maybe somebody helps me here to identify my watch model and finally get work it with video.
I've got an mp4 watch from DealExtreme, here is the foto of it (open the link please, the picture is rather large (1024x768, ~500KB, i'll try to attach small screens at the end of the post also).

The problem is that I can't make proper videos fir this watch, every time I get "Format error" message. I have the original disk and the program called "Video Converter V2.12.01", here is the screenshot. But this program makes .MTV files and my watch even don't display such files when I copy them into it.
Nevertheless the watch came with some came with some example videos, files called "*_NX.AVI", so it sure can play video files, but how to do it I can't understand. I analyzed examples by GSpot, it says that they are MJPEC codec packed, but I tried to make similar files with VirtualDub and still got "Format error" ((((

Nothing is written nowhere about it's model, I heve screwed off the back plate and examined the pcb, but still got nothing but a little label with word "Andalong". But I found name of the chip - NEXIA NX5858. Here is the screen of it.
And here is it's firmware version, it says "Ver 080428"

With the help of Google I found some program that makes .NXV files specially for Nexia chipset (can't remember exact name, they all called like "videoconverter" - but the watch not see NXV too, it seems to see only AVI files. Without knowing the model it's very hard to google.
If anybody knows how to make video for this device, please help me.

Yes, by the way, I can't make JPEG files too. In the watch I found some JPEGs, they seem to be a real JPEG files, my computer can display them without any additional software, but when I simply try to resize my pictures to 160x128 with Windows Paint editor my watch says "Format Error" too or shows blank screen. However, picture converter is not so valuable for me, but I extremely need video tool.

Problem solved. Tons of spended time reading chineese sites did it.
If anybody needs it: The watch model is AD-838, manufactured by: www.andalong.com
Video Converter must be NXVConverter 4.10, older versions not work, Picture Converter is NXPhoto 1.0.2, olders not work too. These programs can be found somewhere in the net, they work perfectly.
Thank you all. The thread may be closed.