I found a solution. On the mozilla add-on page for firefox, at the bottom where it would be easily missed, is a link to install the Fast Dial 3.5 development version. I also seems to have recovered my configuration.
Still, I am greatly angry that the Firefox developers are shortsighted enough to issue incompatible software without an EXPLICIT warning of immanent loss of all add-ons. The attitude that this demonstrates is extremely destructive to the user base.