The following file format/settings for uploading to Show and Discuss work best: -
Eexport as mp4 using the Flashplayer 1220*720 25fps option - this may also create a web page and place the magix swf player in the same folder as the video - you do not need these. Upload the mp4 file as normal
Note if the original video is interleaved format and or your framerate is 29.97/30 fps then you will get some jerkiness on panned shots due to the conversion to progressive format and or pull down conversion.
John Baker was absolutely correct when he told you what you need to do to get your video to upload to show and discuss. He did not spend too much time telling you how to do it. Here is the only way I have ever been successful at uploading a video to show and discuss.