The application apparently thinks I'm constantly scrolling down somehow. I even encountered this problem with this bug-report site, but nowhere else (like in gaming or even on other websites). My PC is running Windows 8.1. I got a Wacom tablet and a Tecknet wireless mouse. I don't know what happend, but now, everytime I come across a scrollbar or a dropdown-option, it just scrolls "down" uncontrollably. I can try and scroll up, but it's just much faster than I can scroll against it. I can't use the program like this and I've started a little animation project in it even!
that sounds like a problem with your mouse or tablet. if it happens with a web browser, there is something going on. I would try to just test your mouse and tablet separately. Having two input devices connected at the same time can cause problems sometimes too.
Yes -- this is not a bug in Krita, but a problem with your system, if as you say your browser also scrolls. A bug is something we can fix in Krita's code, which this, obviously, isn't.