It happened to me a couple of times. From what I can tell this is specific to fbx. Try exporting out your mesh as obj, then putting it back and exporting an fbx.
After setting it up once, that's what it is now for me, a one click button to export all maps with the option to export only the map I'm currently working on as well.
Blender's .obj export script doubles the verticies dued. ;p export and then load it back in blender and you'll see it doubled i think Horrible 1st post hmm
Thats the problem! I can't export from Zbrush to maya...maya starts, but no model inside :( ...but I can export from Maya to Zbrush without a problem..
if you are baking in xnormal make sure to check your export settings on your low poly and make sure you are exporting the smoothing information (smoothing groups)
on export, export tangents and binormals. on import, uncheck import tangents (keep explicit normals turned on). I know this sounds counter intuitive, but it usually works for me.
Thanks for the replies guys. All the uvs there are welded correctly. I'm exporting from xsi and it doesn't have an optimise button during export? Any other thoughts?
You should set the size to 'relative to parent' when exporting for Painter. If you want to use the designer tiling just expose the tiling parameter before export.