Kyle,
I just ran the test again and found that no interpolation was done. I have attached the Z12 2737.png file that was interpolated in yours that no longer is.
Just in case I didn't update the build right on the network, I have placed a new one that I have just tried at
http://www.globalmapper.com/global_mapper10.zip for you to try.
Let me know if I can be of further assistance.
Thanks,
Mike
Global Mapper Support
support@globalmapper.com