These are my settings under Options --> Display:
The font for Tree pane appearance is Tahoma / 8
If it could be of importance:
OS: Windows 7 Home 32 bit
Resolution of the monitor: 1920 x 1080 (but the cutting off happens with other resolutions too)
The DPI-value for text size: 125% (the standard value):
Here the appearance on both ends of the ruler:
a) with tag editor shown:
b) with tag editor hidden:
By the way:
The problem is not caused by the ruler itself. The cutting off also happens when the ruler is hidden:
