I have 4 U1's but I consistently have problems getting them to hash even at a consistent 1.6 Gh/s.  I've tried OC'ing but the hash rate just drops to around 1 Gh/s or below.  Do I need to cool them or just a better hub?  I've got one attached to my laptop's USB port and 3 on a Belkin 7 port, powered hub.

I'm using the newer BFG Miner posted on this thread.

Any help is appreciated.