This is a weird one, and something I'm hoping you guys can help me out with...
I upgraded to the 3.5.1 Rockbox firmware with my Sansa Fuze v1. I've been using Rockbox the last few months without any problems.
About a week after updating, I started having severe problems with my scrollwheel's sensitivity. Sometimes, it would work fine, and sometimes, I'd have to really work to navigate menus - the wheel moved fine mechanically, but it seemed extremely unresponsive. Sometimes I couldn't get any response at all unless I actually clicked the wheel buttons.
Sounds like a mechanical problem to me, and I was thinking I'd somehow broken my Fuze... but before I replaced it, I tried going to Sansa's official firmware. And viola; problem solved! The scrollwheel is acting like new.
Any ideas? I suppose I can try going back to the last Rockbox firmware release, but wanted to see if there were any suggestions before doing so.