Timeline app appears only if page is currently liked

Question

This is the first Facebook App i've created since the Timeline changes. Everything appears to be working the same, except for adding the app to my page's Timeline "Favorites"(?) (the boxes at the top near the About section). A large majority of the traffic to this app will come from visitors seeing the app tab on our page.

I'm attempting to add it using the following URL: http://www.facebook.com/dialog/pagetab?app_id=MYAPPID&redirect_uri=MYAPPURL

Then I select the page, and click "Add Page Tab".

This works fine - I can then swap it's position, view the app, edit settings, etc.

I set up the tab how I want it, and then log out and visit my Facebook Page directly to view the app tab as a visitor would. The app is no longer there. Log back in, everything is fine, log back out, it's gone. It appears that if you do not already Like the page, you cannot see the app. If you do like the page, you can see it. I'd like the app to be viewable by people who do not like the page as well, as the app has a fan gate of it's own.

I've disabled Sandbox mode as well so i'm not sure what's left to do.

Any help is appreciated.

Answer 1

You mentioned in the comments that the app is restricted to US users:

Because your app is restricted, it won't be displayed to logged-out browsers - this is expected because unless the user is logged-in, their location and age can't be determined in order to check the restrictions you've set

If you must have the app visible to logged-out users, remove the API-level restriction and use the details passed in the signed_request to show or hide the app's content

{edit} I missed the edit to your question {/edit} - it may also be that your existing signed_request processing code is failing for logged out users