Having a problem with cards as per the title there. When I view the page source, the meta shows as being set to '1' as well. I don't have a plugin to populate description and title, so those are pulled from custom fields.
I think the problem started after updating to WP 3.9 (tweet from Apr 11 has a twitter card which looks alright) so maybe there's a bug that WordPress devs need to iron out.
I've contacted my host to see if they will upgrade to a newer version of PHP (currently the site is running on 5.3.28) so that might also resolve the issue.
Don't know what else to tell you, except that I really appreciate you sticking with the plugin, it's great. :)