Thanks for your quick reply.
Even on 3g it did not work,
It kept on saying "video not found on Mobileyoutube.com"
Even tho i was on the normal you tube website it kept on redirecting me to the mobileyoutube site for some strange reason and then coming up with video not found???
Anyhow i just upgraded the firmware to version 2.something and now the videos play fine :-)
Thanks for your help