have put together a bit of a compilation of things to try if you are having issues generating new threads.
First thing to try:
Check the length of the title in your thread. Many users have found that cutting down on the title will allow them to post the thread. Give this a shot.
If you are still having issues posting new threads, try this:
1. Delete all cookies, temporary Internet files and other private data.
2. Try a different Internet browser
3. Try a different computer