Seems to be working correctly in 8.5.196. In fact, most any issues I've had with Carrara seem to have been addressed. There are a couple of fringe things that are still being worked on though. 

I have several issues with 8.1 as a result of a Mac OS upgrade. For me, there is a goofy problem with textures. Whenever I apply a texture map, 8.1 crashes. I've gotten around it by  texturing in C7 and then rendering/animating in C8.

However, hair simulation works for me in 8.1. You may want to try resetting Carrara's preferences and deleting the render cache. Hope that works for you.