Thanks for the log. Unfortunately, that's the PHP error log. That's not what we're looking for
The problem is not actually a PHP or coding error. Whatever is preventing the submission on that page is a firewall or security extension. It's likely the mod_security module for Apache webservers. The log we'd need is for mod_security which should show what page was prevented from being executed and why it though there was a security issue with the submission.
If you can't get that, I'd recommend waiting until the v5.1 release (due out next week) which alters the Open Graph creation pages quite a bit. It's possible that will magically fix the problem (though we didn't do anything specifically to fix it). If that release doesn't get it, we'll gladly be willing to access the admin area of your site at that point and see if we can determine what may be preventing the saving of those actions.
I hope that helps explain a little, but if you have any questions, just let us know.
Thanks,
Alex