@Firefly.  Did you notice that copyrightdeposit.com web site is a Canadian company and has a notice in their FAQ you might want to read about "Does CopyrightDeposit.com make it unnecessary to register it with my government?" about going to court in the US without an official US Copyright Office filing.  I can't answer that question or give an opinion other than you might want to look at it closer.  If you have any other questions off-topic from the Panda issue, feel free to contact me at one of my sites.