I'm very sorry to say that the forums are having sum technical issues and u may often get a general error when u post in certain forums (namely those which are being 'Watched' by users), and after registration, in all cases, u get the error when the forums try to send an email to a user.
It looks like this:
Failed sending email :: PHP ::
DEBUG MODE
Line : 234
File : emailer.php
I'm still looking for a solution to this, it maybe a problem in the server side. If u can help bout his, PM me.
In any case, if u receive that error after posting a message, ur message has already been posted and u can click on the DPForums logo to go back to the Index page instead of going back and re-posting.