I have a Nokia 3650. At some point in the last few (2-3?) months, the Call Forwarding application has disappeared from my system menu. The application is still present; I can view it via File Explorer, and even run it. But it is no longer present in the main menu.
I just did a *#7370# to reformat the phone, and the app is still missing.
I'm not sure if it's related, but the CF app seemed to disappear around the time I installed Forward.sis (the app that lets you move files from your Inbox to a save location). That app is currently not installed.
If it makes a difference, I'm with AT&T US.
--Jason