Have you ticked the Transparent box on the layout editor?
If you do you would get similar results to attached picture.
I had a look there are lines on part of the graphic. See Attached screen shot
It is just not visible to the naked eye so easily.
Mala uses the bottom left pixel as a colour reference.
Those lines are part of the graphic, but just a slightly different colour.
You should be able to see/remove them with a decent graphics editor.
This isn't a MaLa issue.