*Reads topic title only*
Try feeding it less coffee and more humans?
*Reads first post*
I haven't heard of a new dretch model, but it could be your inputs. My optical mouse is known to FUBAR on occasion and start moving randomly, causing a shaking motion on the screen. Or, your keyboard could be giving false information the system and making minute jerks in random directions.
However, like Plox said (although I hate agreeing with him), you would need to post a demo for us to really help you out.