when I click on the full extent button the extent dispalyed is taken from the service of the current basemap. Is there a way to show the initial extent instead?
There's a custom add-in available at http://www.arcgis.com/home/item.html?id=a98029bff6684cf49b2b42c58699c491 that I think does what you're looking for. Upload it as an add-in, and then when you add it to your application you can configure it so that the 'full extent' is whatever extent you want it to be.
