Thread:Extension talk:SectionHide/Some odd formatting in MediaWiki 1.22/reply (6)

Have you changed $wgSectionHideShowtop = 0; //default to 1? - this makes the hideall feature keep anything above the first heading visible. It was added for someone who wanted the option to hide everything but I realise now it should default to 1. I can add another option to disable the feature completely, but this may be all you need.