Hello,
I was using the version 4.0.1 and finally decided to update to see if it will fix my current problem. Unfortunately even with the 4.2.0 beta 2 it's still happening.

There is something like a dead zone near the button on the title bar of my windows. The problem is not dependent of my theme (I'm using the basic windows theme), from what I have seen even in Aero I get this dead zone.

I have attached an animated gif which show the size of the dead zone (in the gif I use my middle mouse button click after each movement of the mouse cursor).

Regards,
Froyok.

System :
Windows 7 x64
DisplayFusion v4.2.0 beta 2

I see, thanks for the answer !