firefox thunderbird

[Osmany Guirola Cruz]

Hi people
 I am having a little problem with firefox and thunderbird if i have a 
mail with and url in his body and i clicked nothing happens the firefox 
does not start up , similar in firefox if i have a link "mailto" 
thunderbird does not start up ..... What can i do ? i am using gnome and 
and my prefered aplications are set to firefox and thunderbird