Just a small tip for anyone having issues getting them detected by cgminer, I had to use version 3.1.1 and specify many -S /dev/ttyUSB0 arguments. I've got 4 mining away while I'm at work, will get all of them running at home tonight!
How do you specify those arguments? Can you post your commands? With x'ed out user/pass of course.
I'm running on linux like this:
/opt/cgminer/bin/cgminer -o eu-stratum.btcguild.com:3333 -u DanBUK_1 -p XXXXX -S /dev/ttyUSB0 -S /dev/ttyUSB1 -S /dev/ttyUSB2 -S /dev/ttyUSB3 -S /dev/ttyUSB4 -S /dev/ttyUSB5 -S /dev/ttyUSB6 -S /dev/ttyUSB7 -S /dev/ttyUSB8 -S /dev/ttyUSB9