Ruler is slightly out

[wonea]

Shouldn't the red line be dead on 100? Seems a pixel out.

[praschl]

Yes it should - and does for me

Also all the ruler ticks in your screenshot seem to be slightly off... I had no success reproducing your issue by changing my Monitor DPI. I wonder if there is another way of scaling the window... Which Windows- and .NET Framework version do you use?