According to Ed Thomas, who forwarded my reports to 10Micron as an authorized distributor, the folks at 10Micron have confirmed a flaw in their reporting of sidereal time. According to Ed, they indicated that a new mount beta firmware addressing this problem will be uploaded to the 10Micron forum shortly. Unfortunately I will not get to test if for 3 weeks or so.
Thanks again to everyone here who helped me get to the bottom of this. I must admit, it did not occur to me that the flaw might be in the mount.