Graph starts at level zero, and is also misaligned by a few pixels on my screen. Amount of pixels may vary due to various dpi and resolutions.

Supermechs?

EDIT: I don't see this being BD, moved. Screenshot would be nice.

since when were you head mod?

Problematic pixels are indicated with an arrow. It looks like the black hairline should be either slightly to the right, or slightly to the left.

If the hairline is meant to be centered *exactly* on Level 40, I would recommend replacing it with a wider, transparent yellow overlay. But a hairline between 39 and 40 would be fine IMO.