Jared,
All set now. I made some posts in the Cloudynights thread on this issue: http://www.cloudynights.com/topic/540402-more-sgp-and-asi1600-problems/page-6
Basically the 1.0.2.8 ASCOM driver appears to work, but SGP still has some issues with sub-second frames for Flats. After reading a bit more folks were suggesting that Flats should be over 1 second anyway, so I adjusted my Spike-A FF to get above that and had no issues even with the IOGEAR USB Hub/Extender.