[imaginem]

Hi,

This could be either the encoding or if mime format is not configured to play the video in server.

Could you check the plugin supported formats and troubleshoot page

http://www.longtailvideo.com/support/jw-player/jw-player-for-flash-v5/12539/supported-video-and-audio-formats

http://www.longtailvideo.com/support/jw-player/jw-player-for-flash-v5/40/troubleshooting-guide

Thanks