Ok, I must be bugged, or something, but for some reason, I have to turn off the scroll wheel zoom function on every single one of my characters, every single time I log into the game.
I'm turning it off by hitting ctrl shift F7, because the option to turn it off doesn't show in the F10->GUI->Misc.
Yes, I know, that's where it's supposed to be, a guild mate tried to help me find it, and we talked about it for a while, and ended up deciding I was bugged.