I have an MP4 on my server (usually use Youtube or vimeo) that will not display on firefox.
IE, Chrome and Safari are OK.
The film is cinemascope dimensions - ie 2.35:1
See it here: icmbusinessvideo.co.uk/
Any suggestions?

Hi. The video is playing fine for me so i guess this is a codec issue. Try to reconvert the video using a different software.

Many thanks for a very quick reply.

Do not know why I am failing to see it but (believe it or not) it fails to appear on either my PC or my laptop but appears fine on colleagues computers in other locations. Completely weird!

Have you tried to re-encode the video as i suggested ? This might solve your issue. Also keep in mind that if your devices have not Flash enabled you need to have a recent browser with HTML5 video support. Don't expect this to work in a three years old browser.