Working Rated 5 out of 5 stars
I have it working on Firefox 21 without issues. Just had to go into the xpi file with 7zip, edit the max version in the install.rdf file. I upped it to 25*. Tried running the Weather Channel Desktop program from their website, but kept getting script errors.
Rated 5 out of 5 stars
I'd also like to toss out a Thanks to silverhawk for the fix for Firefox 4... this is my favorite weather extension and I'm glad it now works!