I don't know if this has to do with FF 2.0 or if Logitech changed something about how their website works, but when you select the Button Actions link on the home page and make changes, those changes are not saved when you click Done. If you go in through the normal method (Customize -> Change the behavior of buttons) the changes are saved. I'm assuming this is because there is some information missing for the URL generated for the Button Actions link that is generated by this add-on.