Is there something like Facebook cache?

I migrated an old html/php website to a wordpress blog.
It seems that Facebook can't read my OG data while it is correct in the code.
This means no pictures & likes don't show up in the feed of users.
My Facebook comments are unreachable but they do work.
About 10% of new post does get the meta OG data correct.
Could this have anything to do some kind of Facebook cache?

 

Definitely.

Go here

http://developers.facebook.com/tools/debug

and submit your site.

OG will be updated in real time.