Messaging Help

When ever I go to the administration panel under display and then under heading and navigation, I am trying to post an image for the button of no messages and of you have _ messages. I was able to post the picture for the buttons for every other page: portal,home,faq etc..... but only the mail section wont allow me to put a picture there. When I click save after posting the photobucket image in the slots it says " you must provide a menu name" and if you go back to the mail section under heding and navigation you can not put anything beside the "menu" section. Any help?

Thanks

Change it here
Display>Pics management
Advanced mode.

Thanks for the help, it worked.