Ah! The light dawns!

First, you I daresay you moved her too fast. 10 frames is a third of a second, and in that time she is rotating 90 degrees and moving vertically. Look at the hair that isn't tangled; is that not the sweep effect you get when someone with longer hair falls, or bends over and snaps upright quickly? And I would bet that the swept hair was on the top and sides of the skull. The hair on the back of the skull was trapped between the collision surface of the skull and the force of the rotation and translation over such a short time. Once that happened, your guide hairs would be colliding with themselves and the skull....and any that wrapped around and penetrated between polygons in another group would freeze that simulation at that point. Dnyamics of any kind have to be given time to settle into a starting position, and the denser the collision fields, the more time is needed. I usually -start- at 30 frames to settle, and have wound up having to go to 120 frames in one case before the sim settled out.

The quick and easy location of the collision flag is on the dial controls. Just select the item or body part, click on the 'properties' tab on the dials, and click on the collision detection box you find there.