seems like an unimportant and therefore pointless function on an already rather busy page, if all it does is add a bookmark, which everyone knows how to do. I'd just as soon see the link removed.
Wayne: it calls the sidebar code. In Firefox, that is mapped to the bookmarks.RDF database. In Mozilla/Netscape, it adds it to the panels.rdf.
We picked up the upstream bugfix for this with last night's upgrade.