Please remove all those alien packages you installed with "removepkg". None are needed and furthermore most won't work with Slackware 12.2.
And, firefox-3.0.4 has been superseded by firefox-3.0.15 in Slackware 12.2 anyway, as noticed by knudfl
So download firefox-3.0.15 (you will find it in the /patches directory in any mirror of Slackware-12.2), cd to the directory where you downloaded it and issue as root:
upgradepkg mozilla-firefox-3.0.15-i686-1.tgz
Even better, while you are at it, use slackpkg (it's in the /ap directory of the mirrors) to, as root clean your system:
slackpkg clean-system #check to re-install needed packages afterwards in case you replaced an official package with an alien one
then install all official upgrades, still with slackpkg
slackpkg upgrade-all
if you don't know slackpkg, read its manual first: "man slackpkg".
Please do not use rpm2tgz to convert an rpm package, in most case you'll mess up your system.
Would you need some software not included in Slackware, first look to see if it is available @
http://slackbuilds.org, you can trust them. This is the case for gconf (though you don't need it to run firefox)
HTH