On open-handler won't trigger

I’ve created an applescript application with Xcode. The application does what I want it to. Now I want to add droplet functionality to it. I’ve set up a Document Type in Target Info->Properties. The icon of my application turns dark when i hover a file over it. When I drop the file nothing happens. My application seems to accept the fil, i.e. no error message, but my on open handler won’t trigger. Any ideas why this is?

Hi,

maybe this thread helps