Breaks customise toolbars with FF 3.5 Rated 1 out of 5 stars

I'm very disappointed. Under Mac OS X at least, Link Widgets breaks FF 3.5 and isn't usable. I've reported the following bug: https://www.mozdev.org/bugs/show_bug.cgi?id=21886

This review is for a previous version of the add-on (1.6.6).