Very weird shadows with an animated human

[sideshow tpc]

Hi guys. Have been doing some tests with rendering methods that will work with a skinned animated character in a scene. We normally do fly-throughs that only have the camera animated, but are wanting to ad people in the scenes, and have found that the usual (irr and LC) pre-calculating method doesn't work. So have been playing around with the "animation" pre-render and render settings in IRR but keep running into a prob with the shadows, not so much jittering, but very randomly being very incorrect in certain places. Below is a link to a test render, so would be stoked if anyone might have an idea as to what might be causing the prob...

 

http://www.3dvirtua.net/animation_test.html

 

The problems are around the hood and the back of the hoodie (not so noticable small and compressed, but very bad when on a big tv). It is a character from Daz exported with the Collada thing and I've just linked the bones that came in with it to a bi-ped, but starting to think I'll have to re-skin the characters with physique.....JOY....