Thread:Extension talk:Header Tabs/parameters have no effect/reply

You have indeed discovered a bug in Header Tabs - it looks like it's due to the HTML structure for the table of contents having changed in MW 1.22. I'm looking into it now.

My guess is that those other two flags needed some sort of page refresh; I don't believe that there's anything in Header Tabs that requires restarting Apache. (I don't think anything in MediaWiki as a whole requires restarting Apache, but who knows.)