Wow,
How ridiculous of me not to think it might be the theme BUT it appears to be theme related!
FFS!
I've been using the nevato theme for ages turns out its that theme as I switched to robo spin and it's working fine!
Gah, so stupid I didn't try switching previous just to check!
Thanks!
I'll now try to work out what's causing nevato to fail.
I have edited that theme but nothing to do with the videos though.