In case you converted using WVP, you may want to try using different conversion software and then just upload the converted file. There are a number of free conversion programs available on the web, - Google for it!
I have used "iWisoft Video Converter" (http://www.easy-video-converter.com
) with some success in the past. Start out with recommended default settings for bitrates and framerates. If need be, you can then experiment with different parameter values. Good luck!