Why does my mouse slow down in Paint.NET?

Why does my mouse slow down in Paint.NET?

I used to love Paint.NET. But when I installed a recent version of it (v3.36) in a VMware Fusion v2.0.1 Win2003 R2 machine, I have founded that my mouse slows down in the image area of the application. It's a consistent slowdown that goes away when the mouse is over a tool window or the chrome of the application.