User blog comment:DaNASCAT/Technical Update: November 13, 2012/@comment-1474707-20121113191727/@comment-452-20121117021437

Thanks to Admin_Forum:Weird_effect_with_the_if_parser_function, I've reproduced the problem.

The problem only occurs when links have identical link text.


 * this link - (Help:User access levels#Global level)
 * this link - (Help:User access levels#Local level)
 * different text - (Help:User access levels#Local level)

(I tested, and using different base pages with identical link text does not trigger the bug.)

edit: and as we discovered through CzechOut's problem, this also occurs if the first link doesn't use a section heading at all. Meaning these two links with also be the same:
 * this - (Help:User_page)
 * this - (Help:User_page#More Help)

edit: Another example, showing that first letter capitalisation matters.
 * this - (help:editing)
 * this (Help:Editing#Next Steps)