Quick Silver may be on to something! But instead of saying "leave it" say "here ya go" and teach the command of leave it.
 
Then say "want this?" and teach the command of take it.... 
I saw a dog show once and the trainer just used different words for the commands - like sit meant lay down.  Play Dead meant jump, etc.  It was hilarious because the dog never did what the audience thought is should do - but the dog was doing exactly what it was trained to do!  
