Mine have run 10 days straight with preview firmware and new cgminer... Pretty sure that's a major missing part of the stability equation for many people.
Are you using a pc or pi?
The RPi is a toy and a piece of shit. Why anyone would run thousands of dollars worth of equipment off it is beyond me. Toss it and connect your devices to a real PC or laptop.
Agree the Rpi is for the circus show. Just get real HW and you will not run into all the issues of RPi . 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.