Hi, I’m having a problem making a normal map for my character model in zbrush.
I created the low res model in Maya, and then produced a high res version of it in Zbrush. When I was done, I used GoZ to create the UV map in Maya. Below is an image of this UV map:
You need to flip the texture vertically when going between ZBrush and other apps. It looks like you haven’t done that here.
Sorted it!! It wasn’t that I needed to flip the map, it was caused by the fact that I had messed around with the selecting tool earlier on in the creation of the high poly mesh, and that had caused parts of the normal map to be hidden. Even though oddly enough none of the mesh was invisible. Hope that helps anyone else who has the problem 
and thanks very much Aurick for offerring your advice!!