[CentOS] Need Java plugin for Firefox in CentOS 5.3

Somewhere during the course of recent updates I've lost the Java plugin for Firefox. Not sure when it happened, but I know Java was working in Firefox earlier this year. Firefox comes up empty when searching for a suitable plugin. I'm running a fully updated CentOS 5.3 with the following packages installed:

firefox-3.0.12-1.el5.centos.i386.rpm java-1.4.2-gcj-compat-1.4.2.0-40jpp.115.i386.rpm java-1.6.0-openjdk-1.6.0.0-1.2.b09.el5.i386.rpm

Any ideas what I'm missing? The Java plugin is not something I use often, but when I need it, I need it. Do I need to dump openjdk and get Java directly from Sun? It looks like libjavaplugin_oji.so went away when Sun Java got replaced by the openjdk version.