Rated 4 out of 5 stars

by andyross on July 5, 2009 · permalink

Install the "MR Tech Toolkit". That will let you make any add-on compatible. If you are upgrading from a previous FF, right-click the problem add-on in the add-on manager and choose 'make compatible', then restart FF. For installing new, just put a checkbox in the install box that says 'override version checking' (or something like that.)