Well, you managed to get it to take one new thread with one word, evidently. You should be able to make new posts and threads, as far as your permissions here are concerned.
I suggest you click on the troubleshooting link in my signature line and try those fixes. Good luck!
You were able to post without problems up until 12/29/13. Have you changed your: platform/OS/Browser, since that time? Check through Flockwatcher's trouble shooting guide.
If you have access to another machine try logging in and posting from that.