Thunderbird not opening Url's in firefox ...

Recently I upgraded my PC to Jaunty. Everything went fine, but at some point I realized that Thunderbird would no longer open Url's when I click on them in an email or blog posting.
It seems that Thunderbird did forget how to do it, but it is easy to fix:

1) Open the Settings dialog
2) Go to the Advanced tab
3) Open the settings editor by clicking the button.
4) Search for:
network.protocol-handler.app.http
5) If you have such an entry, you may have to update the path to the browser
6) If the entry isn't there, create a new String item. The name has to be:
network.protocol-handler.app.http
7) Set the value for this property to: firefox
8) Repeat the steps for:
network.protocol-handler.app.https, and
network.protocol-handler.app.ftp
9) Save the changes.

Now Url's mentioned in email and blog messages will open in firefox again.