Attached Link: http://www.philc.net

OK Its not working because some of the model is still intersecting the figure. The solution is to assign the intersecting parts to the constrained group. Also I would not use draping but just calculate a 30 frame animation. This will give you more control over your result. If you just drape you will only have access to the end result, by using an animation you can select each frame.

As an example I used this method to create the freebie currently on my site in the freestuff section. If you examine the skirt you will see the constrained group. You may also find the tutorials on the site of interest. Hope that helps.