Gskinner's shape based hitdetection

if you haven’t seen it: http://www.gskinner.com/blog/archives/2005/10/source_code_sha.html

it looks perfect for what I’d like to achieve but I have a problem implementing it.

It works fine when I have 2 mc’s on stage, but when I want to test collision against a nested mc where it’s parent is not positioned on (0,0) I start to have problems.

See attached file for an example.

Anyone have an idea how to get this to work?