Youtube videos - keep starting from beginning before erroring out.
I'm having an issue with Youtube whereby the video plays for around 1 second before restarting from the beginning. This happens several times before eventually erroring with the standard Youtube error message. I've figured out that the restarting is being caused by the video flicking between playback quality settings. What I can't figure out is why it is doing it. Here is what I have tried, all to no avail:
Updated Flash Player to the latest version
Update Shockwave to the latest version
Updated Java to the latest version
Updated Internet Explorer, first to version 9 from 8, then to version 10
Tried as restricted and administrator level users
Fully unblocked Youtube, and other sites it refers to, in our filteirng solution (Sophos UTM)
Tried several different PCs, of different makes and models
I don't think it's a filteirng issue, because it works in Chrome under the same username and on the same PC. It seems to be a specific IE issue.
Any suggestions anybody has would be gratefully received.