Thanks for the quick reply. Have spent a few hours doing some testing with various programs to see how they subdivide they're uv's. Zbrush and Mudbox recalculate uv's using a linear metho ...
I currently use xsi and have been trying to generate some ao maps. After much crashing and gnawing of teeth i noticed that when i subdivide my base mesh in xsi - which has no overlapping u'v ...