What kind of system setup do you have? I was playing with a couple of these on an 06 Dell XPS M1210 laptop and was getting 1.5 out of one and .7 out of the other. I switched to a Raspberry Pi running a powered Rosewill 10 port hub and am getting a steady 2.0 out of both with the appropriate clock setting. It looks like the onboard usb header on the laptop didn't provide enough juice for both miners to be happy.

Also: Start the miner, grab a cup of coffee, have a coke and a smile, and come back a while later. I've found that the antminers can take a little bit to really find their stride. Hashrates will fluctuate for a while until you find a steady rate. For me working with two miners, I've found that this can take up to 15 minutes. ymmv.