Y O U T U B E: Can't add to my favourites

[MikeyCooperH]

I've added a transformers 3 trailer to my favourites section, i wanted to add Cars 2 for my 4 year old son. Problem is i can't find anywhere, no matter what button i press or screen i go into that says add to favourites as it did with the transformers 3 trailer.

I've checked google out for ideas but no joy. Only found out that others have experienced the same problem.

Any help would be good as i've come to a dead end...