Have you got one of the original ones like mine, then, where the wheel is actually a wheel? They changed that for subsequent versions (10 and 20Gb) to a no-moving-parts glidepad thing.

Yes, and I didn't know they did that. I always thought that the wheel seemed a little flimsy, as it wobbles a little bit, but I've never had any problems with it, other than software beyond the original seems to have thrown out some debounce logic, so that the borders between ``clicks'' seem a little pickier than they once were and sometimes go back one ``notch'' due to the movement caused by removing your thumb from the wheel.