When this happens, the stats displayed by cgminer are shit (and the work is interrupted). The value kH/s is frozen (you have to look at the average 5s which is 0 kH/s). In my case, press G then press R => crash of cgminer (when there is a driver crash, in normal situation, it works perfectly).
If I relaunch cgminer without doing my manipulation => depending on how windows restarts the driver, either shitty hasrate or ok.
If I do my manipulation before restarting cgminer => hashrate ok.
