The scroll wheel on my Fuze seems to swell up and refuse to move whenever there’s a big increase in the humidity.
Since my Fuze is in my car most of the time, I just turn the heater on full and blow hot air over the Fuze for a couple of minutes and that usually unfreezes the wheel. Unfortunately it tends to just be a temporary fix and I have to keep “blow drying” it until the humidity level drops again. (And sometimes cold air from the AC will also unfreeze it since the air from the AC is so dry.)