If the video starts hesitating or playing in a jerky motion just hit stop on your video player and let the file download.
The reason it does this is because the rate of viewing the video is faster than the rate it is being downloaded at.
WMV is a streaming windows file and MPG is a higher quality file but does not stream.
Video's need to be loaded to a server then linked to here.
Some free providers which are good are, just watch the max file size you can load up.
Google Video YouTube FileCabi.net Yahoo video
If you are stuck or don't know what to do just drop me a PM.