I've been mining for the last 10+ days stable@ 470 Gh/s with the old firmware on a Ubunutu 13.10 on Laptop w/Cgminer 3.09h2 , just can't get 3.12.3 to run like it was intended until the FW is out ,as per Ckolivas advice. So put the RPi for FW updates and that about it.
Indeed, it's really bugging me that the firmware is still lagging behind the driver that I wrote for it... 
and i remenber someone said: "... in mining, time is everything.... LOL 