User cannot reply on his own thread

The user "dpocock" has created a few threads [1] [2] [3], but he cannot post a reply on any of them. He says he gets a message saying, "Your content could not be saved due to an error. You may have reached frequency limit." He even tried a day later and got the same message.

[1] https://developer.jboss.org/thread/249337
[2] https://developer.jboss.org/thread/249358
[3] https://developer.jboss.org/thread/249355