update confuses system

[Michael Klinosky <mpk2 enter net>]

Hello.
I installed FC 6 when it became available, and it worked fine. Then, I
upgraded Firefox from 1.5 to 2.0. I needed lots of help - which I got on 
Mozilla's Firefox maillist.

One important note: it was recommended that I install it in /usr/local
(whereas Ff 1.5 is in ~/.mozilla). I think that this is confusing Fedora.

One problem is that clicking on a web address in Thunderbird elicits: 
"There was an error launching the default action command associated with 
this location." (This worked when I used Ff 1.5.) This is with 3 
addresses (in 3 emails, each a different domain).

Also, I can't seem to get the flash-plugin working in Firefox. Actually, 
it *was* working (with Ff 2.0), but I had to reboot. Now, no flash plays 
(including on Adobe's website). Interestingly, there is no message about 
a missing plugin (where the flash should be shown), AND about:plugins 
states that it's active.

What's going on here?