I've worked in the Hair room for quite a while as my store shows and I can definately confirm that collision detection does not work whilst editing (Styling) the hair. The only way to avoid the roots going into the head is to adjust the sliding vert scale and GO SLOWLY. It is also best to use the dials Up, down and back to get the hair pieces roughly in shape before styling and remember once you have started styling NEVER touch those dials again as it will destroy any styling that you have done. I have some hair tutorials on my site HTTP://www.neilp.co.uk that might help althogh they meant as a basic introduction. Good luck NeilP