This forum is powered by phpBB, and in the user agreement, it clearly states that the copyright and link remain. This is not copyrighted by you, so why is your copyright there?
phpBB is licensed under the GPL ( http://www.phpbb.com/support/license.php ).
As far as I understood, there is not such requirement regarding displaying copyright notices. (unless they have another license inside the source package, haven’t looked there.)
Martin
There is indeed a statement about this in the sourcecode of the Template (weird place to put it, is it mentioned somewhere else too?)
it says:
We request you retain the full copyright notice below including the link to www.phpbb.com.This not only gives respect to the large amount of time given freely by the developers but also helps build interest, traffic and use of phpBB 2.0. If you cannot (for good reason) retain the full copyright we request you at least leave in place the Powered by phpBB {PHPBB_VERSION} line, with phpBB linked to www.phpbb.com. If you refuse to include even this then support on our forums may be affected.
I changed the copyright anyway, don’t want to step on someones toes.
Roel
ps. The forum on phpbb.com mentiones a copyright from 2001 to 2003, unless you gave up the copyright on phpbb in 2003, I figure you have to change that too 
I do not agree with the copyright notice, since our template is changed and our content is provided by our users. All copyright notices in the actual php code remain, in accordance to gpl
The powered by phpBB statement is also removed, we’ll probably add something like it again in a new design that is currently underway.
Timothy
This is an automated message - since the last reply was more than 3 months old, I auto-marked it as the solution. If you still need help, just post a new reply.