I looked at the URL that you PMed me. Two things.

1. Your site is not using the Agriya player. You are using the default player that comes with vShare.

2. The problem is that the path's to your video files look like "../../flvideo/somevideo.flv." This will work in Firefox, but not IE (or any other browser for that matter). You will need to change this to point to the full URL to the video (i.e. http://www.example.com/flvideo/somevideo.flv). You can fix this in your player.inc file.