Facebook share on a different domain than your app configuration?

This is the code for the share button:

FB.ui({
    method: 'share',
    href: 'http://cheese.com/',
});

I have multiple domains reusing one app id. We did some workarounds for logging in etc. But at least I hoped the share button would just work. But this gives me a classic:

Given URL is not allowed by the Application configuration.: One or more of the given URLs is not allowed by the App's settings. It must match the Website URL or Canvas URL, or the domain must be a subdomain of one of the App's domains.

The error makes sense: I try to share something on another domain. But why is there this limitation in the first place? Is there a workaround?

Note that the send link dialog doesn't give any problems:

FB.ui({
    method: 'send',
    link: 'http://cheese.com/',
});

What's so different between share and send?