Can't play the video transferred to my iPhone 4?

I've used a program called Syncios to convert movies on my computer so that I can then transfer with the same program and view them on my iphone 4.
I'm positive that I got the right format and such, the only problem is when I enter the video app the movie is grey. When I press the movie nothing happens, I've also tried restarting and such but it doesent work. What does it mean that the video is grey? Some kind of buffering or is the movie too big? But that would be weird.

Check the settings on your computer with the the program

I think that might be two possibilities
first, might be the code problem( your converter's problem)
second, are you sure the whole file has been moved to your iPhone? Did you cut it before the buffering was done?
If you need another converter, I have a recommendation:
http://www.iorgsoft.com/Video-Converter/ (there's also mac version)