YouTube playback error on iOS 6 behind proxy

Hi everyone,

This is about iPads running in enterprise environment behind proxy. Since I update the iOS, the iOS 6 devices do not play YouTube mobile site in safari at all. It receives error says the video is currently unavailable. If I use YouTube App, it plays only a few video clips. It will return a playback error with most video clips. The current iOS 5 devices have no problem play YouTube from either App or website.

Extra information:

The iOS 6 devices play YouTube fine outside enterprise network without proxy; the iOS 5 devices play fine either way whether behind proxy or not.

Apple really ***** and do you guys have come cross similar problem?

Thank you very much.