just to re-inforce what has already been said, i think its completely normal behaviour, deefer has been doing it an awful lot.

I have just started the biting recognition thingy from the 'bite stops here' link. i let him have a little nibble on my hand etc at the moment until he bites a little too hard then do a dramatic 'ooowww that hurt' and walk away, ending his playtime. he is responding very well and generally now he just gums/mauls instead of bites. next stage coming up i think.

i also found that when i started making him sit for everything, food, lead, fuss, cuddles, praise he has become a lot calmer. when he jumps up he gets a NO and generally falls straight into a sit position hoping for some praise!