I am having the exact same problem with my Hav. He is 7 months old now and STILL does the same thing. I have bought him 3 difference collars, now he has the smallest, lightest and thinnest I could find that would still fit him. He still hides under furniture and doens't move for as long as the collar is on. I end up feeling bad that he is miserable. I hate to give in but I can't stand having him be so unhappy.