[CentOS] Centos 5.5 + firefox 3.6 and 64bit javaplugin (1.6u23)

> Looks like firefox is 32bit version, not 64bit version, but 32bit java
> 1.6.u23 still fails.

Where did you install Java from?
The Java browser plugin is not available in teh OpenJDK shipped with CentOS 5.5.
You need to install the JRE from Sun.

In this page:
http://wiki.centos.org/HowTos/JavaOnCentOS
the following tutorial is recommended:
http://www.trading-shim.org/faq/?java