XBOX 360 mce wont play mpegs....

[Justinvz77]

HI All...OK, i have joined this site as a last resort to ask the experts for some help.
I will try and keep it simple.
I want to play mpegs on xbox mce.
MY mpegs work fine on my vista laptop through mc, so the actual mpeg is fine, and i have the codecs. All works fine.
My Xbox though comes up with the error Video Error - Files needed to display video are not installed or not working correctly. Please restart Windows Media Center or restart the computer.
I tried playing the same mpeg from my friends laptop to my xbox and it worked beautifully.
I tried again from my laptop to xbox with a direct network cable (no router) and it still didnt work. So its not my router.
My conlusion is it must be a firewall problem, or security problem that will not let video be sent out to the MCE. Any suggestions?

MY Laptop is a Toshiba Satellite with Vista home premium
I use AVG antivirus. Apart from that, its pretty much just a new laptop!

[logifuse]

Exactly what sort of video are you 'mpegs'? MPEG2 or 4? THe Xboard 360 will only support DVR-MS(live or recorded TV) & MPEG2 through the Extender interface.

Justin