I think the problem seen in GeoDav’s video - regarding the tangent stuff - can be fixed by hitting the ‘Update Tangent Space’ button under the ‘Input Mesh’ tab before saving out the apex file. Certainly it made the error message and artefacts go away for me on the simple test model I was using. I can’t speak for anything more complex however. That’s for this afternoon I suppose!
Oh I suppose I should say that this was using Blender 2.71.5.