Rated 5 out of 5 stars
It was great,
but v.501 does not work with Firefox 3.6.15 (latest),
Went back to "Open With" version 5.0.
just like many other people,
I will stick with Firefox 3.6 series,
until FF 4 "stabilizes", in the future.
(I love my FF extensions *too much*, to jump into the FF 4 hoopla & extensions headache...).