[MonoDevelop] Can't sign my MonoMac app on monodevelop

[Maurício Linhares]

Hello guys,  

I'm trying to sign my mac app but the option is not enabled on MonoDevelop. Is there anything I should do before signing the app?

I see the identities listed on the combo box, but i can't click on it -> https://skitch.com/mauriciolinhares/ews6h/project-options-sample-app

Hints?  

-
Maurício Linhares
http://mauricio.github.com/ - http://twitter.com/#!/mauriciojr