Attached Link: http://www.keindesign.de/stefan/poser/firefaq.html#14

I think the trouble is just the sheer size of the textures on Neftis' hair, because if you reduce the size of the textures (by resizing them in Photoshop), that fixes the problem. Firefly has problems if you have a lot of large textures in a render. *Just what causes the Adding Objects... freeze ?????* IME, it's a memory issue. See number 14 in Stefan's Firefly FAQ for what you can do free up some memory. (The MilHorse takes a lot of resources, or so I've heard.) Poser just doesn't use system resources very efficiently. Even if you have a state of the art computer, rendering in Firefly can be a challenge. (If you haven't upgraded to SR4.1, doing that may help, but don't expect miracles.)