For Mac Powerbook G4 (10.3.9), downloading Firefox "3.6.24 dmg" always fails to "verify" and when opening the archive it says the dmg is corrupt. This version appears to be the latest one that will run on this system.
Now using Firefox 18.104.22.168. Running okay, however can't access cetain sites. Only want to upgrade enough to get by.
Firefox 3.6 versions aren't compatible with OSX 10.3.9, Firefox 22.214.171.124 is the last ever release for Mac OSX 10.3.9 and earlier versions.
Get it here: