I'm still at it with the random no-hashing issue I keep having everyday with my Raspberry Pi & now 8 Gridseed G-blades, up from 6 G-blades, new 6FT USB Cables (down from 10 & 15 footers). And again, I even replaced the hub with a new Turcom 24 Port USB 2.0 Monster USB HUB W/ac Adapter Power Station.
I have only 2 g-blades running but i seen this often before, the only way i could get the 0 hashing away was after i turned power off on the failing one and power it back up.
minerd written by siklon (cpuminer-gc3355 v1.0e) has by far the best and most reliable built in automatic method of soft resetting stale chips, it's controlled via --gc3355-timeout switch, you just specify number of seconds after no share is submitted before restarting chips, in my experience works every time and it has yet to let me down.