Firefox uses wrong app for mailto: links

On an XP system: When Firefox fails to regard Thunderbird the "Default Mail Application" (even though you set that elsewhere) the problem may be solved by:

• Opening the Control Panel

• Opening the Folder Options

• On the File Types tab, find the (None) URL:MailTo entry

• Click the Advanced button

• In the Actions window, you should see the entry:* open*

• Click the Edit... button

• Set the Application Used to Perform Action to the correct path of your Thunderbird as:

  "C:Program FilesMozilla Thunderbirdthunderbird.exe" -compose "%1"