jQuery 1.3 works fine in FF 2.0+ and partially in 1.0.x and 1.5.x - is there a list of functions that fail with these old browsers? Even an incomplete one would make it easier to go around the problems.
I know, users should upgrade their browsers, FF 1.0.x and 1.5.x is ancient history, etc, but: a) as IE6 proves without a doubt some people will not upgrade b) these people visit my websites to give me their money - I want to deliver full functionality or be able to gracefully degrade to ensure that every single person who want's to let me earn some $$$ has the oportunity to do so :D