I had a similar problem. I found that anything in 16:9 format was ok, but all my 4:3 ratio videos wouldn't work. I tried every video player I could find in the market, and none worked.
I found the problem was the video resolution. on the vertical axis it was lower on the 16:9 format, usually 420dpi. ON 4:3 it was 520dpi+, which is too high a resolution for the phone to read it.
,
Lowering the res for 4:3 vids to less than 480dpi and it works fine.
hope this helps,
marcel
