weird mouse & opera tab change

hi
whenever i right click and move the scroll wheel, opera changes tab. how do i disable?

for some reason my scroll wheel seems to be half on and half off, when i click something on any scrollbar be it webpage or explorer, it scrolls up and down and i can't click it, i have to scroll more to get it unstuck.

Opera sucks sure there's an ebuild for opera but it just get dropped to /opt, it's statically linked, and it's CLOSED SOURCE, which means that it is a BINARY package.