[Trouble1]

Thanks guys for the suggestions, I am going to start immediately to work on reinforcing the "quiet" with the clicker. She is already trained to it.

If I understand correctly, I will need to provoke the behaviour, ignore it and then reward her only when she goes quiet. This will have its challenges as unfortunately she doesn't vocalize on her down stays at home, but I respect what was said about the lineup and the stress on the other dogs. In fact, if I ask my dog to do a down stay outside of the lineup but still in the training facility she will do so without the grumbling, it seems to only happen right after doing the long sit and the going directly into the long down. But all of you are right it isn't fair to the other dogs and perhaps I can see if the trainer will let me continue with the rest without participating in the long down until I get this cracked.

Her other behaviour is excellent during the class and her response to the other commands are immediate and silent.

Thanks again this has been extremely helpful.