kaharzSo I'm an idiot, but I thought I'd share in case anyone was as dumb as me. I have a logitech M705 mouse that I got to replace an older one that died. It has made MC a pain because the mouse wheel is super sensitive. Sometimes just grazing it with my finger or clicking the the left or right button would cause it to switch items on my tool bar. I searched far and wide for a solution and couldn't find one that worked. Other smooth scroll mouses (mostly MS and Logitech ones it appears) have the same issue. There is an MC bug report and a forum posts about it happening in other games. For some you can turn smooth scrolling off in the options, but mine didn't have that option. What it did have was a button on the mouse that I had ignored for, oh about 6 or 7 months probably, that switches between smooth scroll and regular scroll. And that fixed it.