These threads is a little different problems but I explained how to teach "Drop it" there so you might want to try this method. Let me know how it goes.
[url]http://www.kingdomofpets.com/dog/forum/dog-behavior-problems/548-dog-plays-keep-away.html[/url] [url]http://www.kingdomofpets.com/dog/forum/dog-behavior-training/1260-retrieve-give-back.html[/url] Good luck