ChalklYne

Say you import a low res object... then subdivide it while smoothing is on... then you sculpt and do your thing... well the UV coordinates on the original mesh get warped and smoothed when you smooth the mesh

So, you have to export the newly modified mesh to have the texture map be for the mesh it was intended. If you try exporting a texture and applying it to the same mesh you imported without re exporting it back out of zbrush then its normals havent been smoothed in correspondence to the UV

Export the original low poly from Max/XSI, then export the high poly from Zbrush. Then just use Xnormal to export maps.