OK, sorry, thought it was on all FF skins... I do use TGTSoft Style XP to change skins and themes, but didn't think they would add a link like that.
It's been awhile since I used the default FF skin, so I forgot what it had.
I do use Adblock, a FF extension, and it has the same puzzle-piece icon, maybe it added the link, not sure.
I use the Nautopolis for Firefox 1.0.26 theme, by Alfred Kayser, if this helps.
Although, it's re-skinned by Style XP.
Just click on it, and it checks for updates for the browser and all extensions installed, just what you were askin to do.
Hope it helps ya.