After more then a year of silence, I released a minor MW 1.16 compatibility fix for HeaderTabs (v0.6.6).
I also moved repository to Wikimedia repository so this release is available here:
and latest development code is here:
If you're using Sunversion, you'll have to remove the old version and checkout from new repository again
svn co http://svn.wikimedia.org/svnroot/mediawiki/tags/extensions/HeaderTabs/REL_0_6_6/ HeaderTabs
Hope this version solves the issue for MW 1.16 and up, let me know if it works for you.
CCing SMW dev and user lists as it seems to be popular there (thanks to Yaron promoting it with SF ;)).
P.S. I still hope to spend some time upgrading to latest version of YUI as well, but another time.