Sorry Morbius SP is giving you so many issues, maybe when they get the Mac side fixed they’ll give you another 30 Day Trial for helping them by pointing out some Bugs, seems Fair.
Guys dont let me steer you away from Zbrush by showing off SP, Zbrush at its core is still a Great 3D painting program, so dont feel you cant paint on your model in Z. Youve already got the UV’s and everything set-up for export, why not skip SP and paint in Z. Go to this link for an in-depth course on sculpting and painting with Joesph Drust, its a excellent series. http://pixologic.com/zclassroom/home…-joseph-drust/.
Don’t be sorry! I’m just happy to have got (gotten? git 'er dun?) as far as I have, thanks to you!
I actually started SP again from scratch, and stepped down to 1024, and it’s working again! I did all my mapping in Modo @1024 with excellent results anyway, so what the heck. It worked! I got the rust, etc., done, but I’m afraid you lost me at the point where you used your self-constructed ‘Smart’ dirt material. Couldn’t follow how you built that, so I skipped it. 
Anyway, STILL moving forward. I don’t give up easily.
Yeah, that Helmet Design with Joseph Drust. I got about 14 videos in, and he started jumping ahead with the actual helmet sculpting (i.e., instead of showing ‘how’, would say things like 'I sharped up these edges, and I did this and that…" without showing HOW to do it) and totally lost me. My helmet wasn’t anywhere near what his looked like, and I just gave up on that. It’s a common mistake people make when doing tutorials. Presuming too much. Needless to say, I had a lot of time invested, and was pretty disappointed when he started making big jumps ahead. Can’t complain too much with free tutorials though, you know? It seemed awfully good, and looked like fun, but…….
Anyway, I’m still at it, Glenn!! 