I did the 49.9k resistor mod, but I'm having an issue:

For some reason, although the Gridseeds are running at 7.65 Mh/s collectively, I"m only getting around 3.6 Mh/s effective. It's like this no matter what pool I use. Is this normal, and if not, any idea on how I can fix it?
Can yopmeone join in here and tell what the actual problem is ?
I have to say that i face the same problem with the bfgminer.
On Ubuntu when i use cgminer, i have to restart cgminer very ofter as there plopps an libusb error. On BFGminer verything runs as it should but the effective hashrate is extremely lower...
A win 7 32 or 64 bit host, a USB hub and cpuminer will solve all of your problems