I've been using Keylight to do some green screen work and, basically starting from scratch, went through a number of tutorials, including three from The Foundry for Nuke but which are applicable to After Effects. All the tutorials, however, are general and don't deal much with pulling difficult keys, such as shots of little girls with frizzy hair. I've gone about as far as I can go with what I've learned and my results aren't very good: the hair in the transparent areas chatters like crazy. Fortunately I'm scaling from full HD down to 720 X 405 so some of the noise becomes a minor problem. However, there is one shot that is really not acceptable.

I'm using a pre-comped layer to create a matte for the same layer below it, trying everything I can but still missing it. I realize this may be difficult to answer without seeing the project, but any tips anyone might want to offer would be much appreciated. (CS 6, Keylight 1.2) Thanks in advance.

Jonathan