... hashrate drops from 30.5 Mh/s to 22 Mh/s, and returns to 30.5 Mh/s exactly when i move my mouse.
Also I've been mesuring power comsuption while in 30.5 Mh/s and while in 22 Mh/s and both are the same. It doesn't save any power...
Assuming it's not a miner bug I'd guess that this is something that you probably could be get rid of if you play around with windows.
Change power options, disable other running tasks, remove windows crap in gpedit.
However it could be that you need to fine tune your card(reduce volts?) to make it stable and "returns to 30.5 Mh/s exactly when i move my mouse" is just a coincidence.