Rated 5 out of 5 stars

le marius7x ar Meith. 18, 2008 · buan-nasc

I knew the way to make a add-on compatible, but it did not work from first try after I modified the rdf file (it kept saying that the addon will be installed next time FF3 starts). But worked the next day, after a restart..
Also, you can try MinimizeToTrayEnhancer add-on, and then add a toolbar button that minimizes FF by customizing the toolbar buttons.