Cseider,
Facebook is always changing a bit, and while this has been a problem in the past, we haven't heard of it recently.
You won't see the fb:admins thing in a wireshark packet. It's something on the page itself that Facebook sees and uses. They don't scan it when the page is loaded though, they're like Google and will periodically visit the page. With that said, can you try their Debug tool to see if you get the same error, or if the fb:app_id is set properly? The App_id is similar to the admins tag, and either is allowed to be used:
developers.facebook.com/tools/debug
Once scanned, this also updates Facebook as if they had just visited your page and may possibly clear the issue up on it's own. If not, if you can, please post or Private Message me the URL of a page with the problem, and we'll investigate further.
Thanks,
Alex
And again: Like it
