thanks all. WDT it is. (maybe next time I'll try doing a little more research on the site before i throw out a question that's probably been answered here many times over!)
FWIW though, i have never had this "problem" before and had been using my rocky for about 2 years. but then i probably shouldn't be surprised that moving to China, buying a new 220v rocky and trying out new types of beans might mean some other minor adjustments, too.