MoFo just released Firefox 1.0.3, which fixes some security issues. Unfortunately it also breaks some extensions. Even more unfortunately, from my perspective, MakeLink is one of the few extensions it breaks. The fix was straightforward, and is basically described in full by this Bugzilla comment. MakeLink 2.0.1 incorporates the fix and will therefore work with versions of Firefox from 0.9 to 1.0.3.