Thunderbird does not allow anymore to open url links with the predefined browser

Question

I'm just switched from XP to Seven. I have transferred my Firefox and Thunderbird profiles to my old XP pc to my new Seven pc. Firefox and Thunderbird work as expected, apart that with Thunderbird now when I click on a url inside a message text nothing happens, while before the browser window was loaded and the url page opened. What could be the problem source?

Answer 1

I give the answer by myself. Solution is here: http://getsatisfaction.com/mozilla_messaging/topics/thunderbird_does_not_open_links_if_ie_or_firefox_is_already_open

Set network.protocol-handler.external.http to true.