My biggest problem now is that although I *can* get good speed from the Antminer, it doesn't hold.  It'll run at 1.6Gh/s for a few hours and then drop down.  Then later randomly pick back up.  In the chart below, the blue line is a little USB Block Erupter staying steady, but the black line is my flakey Antminer.  (different computers)
 
What is the deal?  I'm really hoping this external powered USB hub helps this.

http://i.imgur.com/EsI3PJS.jpg