correct way to set firefox/thunderbird as preferred brower/mail client

[Mr R A Mercer]

Hi

Just installed FC2, I want to use firefox/thunderbird builds from 
mozilla.org but am having problems setting the programs correctly in the 
Preferred Applications preferences.

Currently I have

/home/ram/firefox-0.9.3/firefox %s
/home/ram/thunderbird-0.7.3/thunderbird %s

set for browser/mail client respectively.

Clicking on a web link in thunderbird opens in firefox fine as long as 
firefox is not running, if it is I get the Select Profile window 
(similarly for clicking on a mailto link in firefox).

How can I get it so that the respective link opens as expected whether 
or not firefox/thunderbird is running?

Cheers

Adam