From Jeff Arbuckle, May 9 11:37:12 2005.
You will need to edit your prefs.js file in your mozilla profile.
For me the file is located at ~/.mozilla/Default User/edf44w6r.slt/prefs.js, other user's directories will be different.
Make sure that mozilla is not running when you add the following line to prefs.js:
It looks like this option was included in Fedora's official mozilla-1.7.6 package.
TCC System Programmer