As you can see above I can make posts as well, I just can't create new forum topic. I even tried to change new topic's content to quite different and nothing happens again...
edit: somebody had just created new topic... so there is some problem somewhere on my side probably... :/
I first wrote something like post posts, sounded so stupid that I erased everything and left out the part with not really the same as opening a new thread ;)
And otherwise the two most common problems, length or broken [ ] - use.
Or did you try to use a too long title? What was it again 20 Characters or something?