Location Type Charater
The character location seems to be calculating lines position incorrectly. In the image the gray line is the eclipse print margin (with all its new crazy placement rules) set to 80 characters, the red line is ArbitraryLines value for and the end of '+ 80' is the actual position of 80 characters.
Before eclipses changes the gray line would sit at the '+ 80', ArbitraryLines has to be set to 75 characters (just to confirm offset is 0).
I am making a guess here but I think the issue may be down to the assumption that a fixed width fonts height is the same as its width. If I change the font to one where the width and height are the same then the line is correct. However changing the font to a fixed width font with a width different from its height results in the line being incorrect.