When I try to post in Gambling, it gives an error message saying that I have already posted, when I have not!

Here is the link to the error:
https://bitcointalk.org/index.php?action=post2;start=0;board=56
Here is the screenshot:
http://i.imgur.com/P0O4r8q.png

Yet, here is the forum, and there are NO posts by me!
https://bitcointalk.org/index.php?board=56.0

Not only that, but now I'm getting this error when trying to post this error report!
http://i.imgur.com/eVh9Uie.png