Cauterite

Alright I see now; I installed GIMP and saw that by default its brush tool behaves quite the same as P.N's. But when I changed GIMP's brush "Spacing" option to 1 (from the default 10) it was perfect. Is there no way at all to adjust spacing in P.N? Photoshop seems to have an option to disable spacing entirely.

I'm pretty new to Paint.NET, but I'm sure this isn't right. The brush tool (and various others) aren't painting smoothly at all; see this video for reference: I'm sure you'll agree, the issue is pretty obvious in the video. I've tried various things: toggling hardware acceleration, antialiasing, hardness, brush size, blending modes, canvas sizes… but nothing helps. Same behaviour in every case. Diagnostics page: Thanks for your assistance.