but you got accepteds after the error starts. once I get that error they display OFF, I haven't experienced ZOMBIE yet.
and sometimes I just have to restart cgminer, and sometimes I have to unplug/plug the stick and restart cgminer.
I did find that they run better when I have a separate cgminer for each stick.
I have the same here, when they go zombie, I quit and than restart and it works again, some times I have to turnoff the hub and turn on again.
I just have tried with 100 mhz, and the problem persists!
I'll try running different cgminer for each stick!
And actually I can run each one at 250mhz! working with no hardware errors!
So I did, running 2 sticks in different cgminers at 250mhz for more than 14 hours without a break, it´s definitely the solution. No problem here.
So my guess it´s the 2 pack stick going zombie or off, it´s a matter of driver or cgminer bug!
It´s definitely not a problem with the hub!
also what is your cgminer version? I grabbed 2 of them, to see if there was a difference, so I have 495461c and b682468