Bug in forum registration

Hello, when a user tries to register for your forums and chooses a user name that is too short (the one I tried was 3 characters long), the following message appears:
Special characters allowed are hyphen(-), underscore(_) and space( ), but not as the first or last character.

I was about to give up already...

I'm guessing that is a bug caused by copy/paste of the message for the validation.

It would also help, if the field in which the validation error occurs was highlighted.