Not sure if I'm missing something, but it's not working for me..
Fragment of a discussion from Extension talk:Header Tabs
I checked your Special:Version and as mentioned in an earlier thread HeaderTabs not Working in MediaWiki 1.17.0, the Usability Initiative Extension does not work with HT and 1.17 due to an jQuery conflict. Please note that the Extension:UsabilityInitiative is deprecated and it is recommended not use it beyond MW 1.16.
