Paint Tool SAI's zooming is inverted. That is, when you scroll up on your mousewheel it zooms out, while in every other program that doesn't have a crayon up its nose zooms in instead. And vice-versa.

 Shadowsunderer made me fix it, because I couldn't look at him going back to MS Paint because of SAI misbehaving like that.

It only requires a tiny modification to the sfl.dll in SAI's Program Files folder. For fear of copyright infringement or whatever, I don't want to upload the file itself, but here's the patch:

1sPEAAQgc2ZsX2ludmVydGVkc2Nyb2xsLmRsbC8vc2ZsLmRsbC8FnsAAABqewAAAAgkEGCZ3FvfaE4SlAQMTmpp9AISlAw==

Base64 decode that (I think certutil does that in Windows?) and apply it to SAI's sfl.dll with xdelta3. Alternatively, find me someone that doesn't afraid of hosting the DLL in their Dropbox or something.

Or if you want to flex your hex editor skills and patch it manually, insert `f7 da` (this adds a neg %edx instruction, which flips around the scrolling offset) at offset 0x11281 and remove two 90 (no-ops following the subroutine) from the bunch of them that start at offset 0x112ac to align the rest of the file again.