Firefox 2.0.0.8 has been released with support for Mac OS/X 10.5 (Leopard) and fixes for a number of bugs.  There are more details at http://en-us.www.mozilla.com/en-US/firefox/2.0.0.8/releasenotes/ and http://www.mozilla.org/projects/security/known-vulnerabilities.html#firefox2.0.0.8 .  Thanks to Paul, Jerry, Roseman, and Gilbert for sending this in.