FC3 Thunderbird links not working

After updating from FC2 to FC3, (the system is fully updated), My Thunderbird doesn't trigger any more my Firefox, when I go over a ling of the kind http://www. etc etc on any mail I get. They were working fine on FC2, but Mozilla was still there:
What is the point to be investigated (any setting in Thunderbird???)??

Tnx for help

--

Antonio M.

===================================================================
Working with  Mozilla Thunderbird 0.9 on Redhat Linux Fedora Core 3
===================================================================
===================================================================
    Uso Mozilla Thunderbird 0.9 su Redhat Linux Fedora Core 3
		www.montagnani.org
===================================================================