Where does mozilla mime and application info come from?

[Steve Bergman]

I'm wanting to upgrade a couple of my fedora and rh9 users to the 
generic mozilla 1.6 version from mozilla.org (i.e. not rehat/fedora 
packages) since their spam situation is beyond spamassassin's 
capabilities and they really need a Bayesian filter.  (Spamassassin's 
good but these users have very public email addresses and receive a 
great deal of email that looks a lot like spam but is not.)  However, I 
want to be able to compare their current mime type definitions and 
desfault apps to the new ones in 1.6.  All this used to be done in 
edit->preferences->navigator->helper apps.  However, that does not seem 
to be the case anymore.  Where is this information kept, and should I 
expect a new generic install to pick up the same information as the 
redhat mozilla included in rh9 and FC1?  Or is there a way to plug in 
the junk mail capabilitis to an earlier RedHat/Fedora version of Mozilla?

Thanks,
Steve