There's no hosting account associated with the forum account you are currently using, what cPanel name did you sign up for (has a max of 8 chars)?
Seeing you joined the forums recently it may be that the creation of hosting account failed, in which case you'd need to sign up for that again at:
http://x10hosting.com/signup.php
When asked about forum account on step 5 just enter the details of your existing forum account.