i have an 11 month old staffie bitch.  She loves people and dogs and has a great temprement.  However, i used to have some problems with her on lead when another dog approached, she would start growling and barking (staffies owners, u kno the over the top growl they make when they are playing, its like that), anyway, i solved this problem by not tightening the lead when we saw another dog as indie was picking up on my tenseness.  Now it seems, that i dont have a problem unless the owner of the other dog is pulling theirs back or tightening their lead.
Just yesterday we were walking along when we were coming towards a black labrador, anyway, the woman tightened the lead and indie started growling (indie was showing signs of submission b4 she did that as tho she wanted to play), so the woman crossed the road.    Thing is, if indie hadnt already started i would have told the woman she was ok and to let her dog meet, but as indie was already growling i thought it a bit inappropriate and just walked on.

Does anyone have a solution to this?  She is great with other dogs, especially offlead up the common.  infact, she will play with one dog offlead, but the same dog offlead with the overprotective owner and she growls at him.

ive got exactly the same problem, but i wouldnt call it agression, keisha plays really nicely, boisterously, with other dogs when shes off her lead or in the house but when shes on her lead she goes really crazy jumping round in circles, flipping herself ova and doing a play growl type noise, other owners look at me as if 2 say that i am being cruel 2 her, but i dont no what to do either, it happens exactly how you describe it, when the other dog owners pull their dogs back, so i think it is some kind of frustration keeping in2 the equation.  if the owner of the other dog doesnt do anything then she is fine, the problem ive got is that ive run out of helpful dog owners to practice on, and she knows what will happen with those ones now.  any help very much appreciated.

ah im glad im not alone!  i didnt think it was aggression either, but im not brave enough to stop the other person to find out!!!

My Lhasa Apso bitch does this too. When on the lead she barks angrowls at other dogs she does not know, i said to my vet and she suggested letting her off the lead as when she is on it she is using me to back her up when another dog approaches that she is not sure about i did this and she was quite happy a bit too happy as she chased after the dog in the park so i had to follow.