How To Diagnose and Report TeXShop Bugs
TeXShop bugs should be sent Richard Koch, firstname.lastname@example.org. Bugs in the TeX distribution should be reported to the author of the implicated tool. One way to diagnose typesetting bugs is to typeset from the command line and see if the bug is still present. If so, report the problem to the maintainers of TeX; otherwise report it to Richard Koch.