Hair >Children>Interpolated>Virtual Parents Crashing 2.5.7 (38094)

I have a model with a single particle hair system.
It has 20 parent hairs.
I read that using Virtual Parents will improve the look by giving more nucleation points for clumping the child hairs.

The problem is if I set the virtual parents above 0.1 it instantly crashes Blender.
I’m using release 38094.

Anyone else have this or similar problem with Virtual Parents?

Thx