Hi, I have a 3GS on 4.2.1, jailbroken with greenp0ison.
I have noticed over the past few days that YouTube is no longer working over 3G, it gives the message that the "movie format is not supported". However, when connected to wifi, it works perfectly. It occurs with small and large video files so I don't think it's a file size issue.

I have looked around and this appears to be a common problem on devices, without a conclusive solution.

Can anyone help me with this?