Just out of curiosity, what USB hubs are you guys using? My Ankers for some strange reason do not work anymore, on either windows or linux. Must be some sort of weird usb 3.0 bug in those hubs, or some weird cgminer issue.
Finally got use out of my Mondohub 28 port !
Where possible, try using USB 2 ports vs USB 3 ports, I've found.