This has now happened a couple of times....
I usually use the quick reply option to respond to a thread. Sometimes (not always) when I hit the submit button, it goes to the full view page but actually posts the thread as well. At first it looks like I haven't submitted it as all the text is their but all the icon options etc are now visible. If I hit submit again however I recieve a message saying you can't respond so quickly to the thread, yet if I go back to the forums my post is already there.
I guess this is not a huge issue and it is intermittent but it really shouldn't be happening.