Okay so I'm new.... I get it...
...but I've attempted to post a topic here.
First try : You just posted less than 360 seconds ago - please try later. (I didn't)
Waited 10 minutes and posted again: You've already posted this topic. (...but its not visible anywhere!)
Finally posted it. Saw it in the forum. 10 minutes later? GONE.
WTH?
You need to make sure you wait the full six minutes before you attempt to post. Logging in and attempting to post reset the timer so just make sure you wait the full 6 minutes then try again and you should have no problems.