Hi. Sorry for my English, I speak Spanish. I'm making a game and I'm using Drag & Drop behavior. I made two walls (wich are invisible) and when the object (in this case is a box) collisions with the wall you can't continue moving (it's like an area for Drag & Drop). But when you drag very fast, the box can overstep the walls.
If you don't understand anything check my video. It will be more easy: tinypic.com/player.php (Please see it)
Thanks!