Why is Youtube slow all of the sudden on my IPhone 4?

It use to work fine a few days ago, but now it's taking forever to load videos. Youtube works fine on all my other devices. Has anybody else had this problem/know how to fix it?

Wi-Fi or cell?
Are you looking at it on your 4 and just checking to see how it is on the others?
You tube has a bad habbit of limiting when it is getting used alot. I usually get 3-5 consecutive vids…
How is the speed of other things like your browser?
Done the basics?
Disconnect from the network, reset your phone…