It's because the normals on the cuffs are facing the wrong way. You need to reverse them. You can do it in Maya, simply select the offending faces, and then go to Normals>> Reverse. That should fix it.
If you can't tell exactly which faces are the bad ones, in your view-port sub-menu, Go to View>> Backface culling.
This will make the bad faces invisible. (you can still select them though).
EDIT* Scratch that.
Your normals are fine. It's because you only have one layer of polys. Zbrush by default uses back-face culling.
To have Zbrush display both sides of the Polymesh, go to (in ZB) Tool>> Display Properties>> Double.
"Your weapons are no match for ours! People of Mars, surrender!"
"Um, this isn't Mars. This is Earth."
"Earth? Earth-with-nuclear-weapons Earth?"
[long pause] "Friend!!"
Last edited by Mayaniac : 23-03-2010 at 05:06 PM.