In the U.S., if you created it, you own the copyright, period. You can give it away, license it, sell it, whatever, but you start out with it. No one else can give it away for you and giving it to someone for A does not mean they are authorized to do it for B. You do not need to register it, but registration makes it easier to prove that it is yours.
If it is yours, you should be able to do what you want with it. There will be naysayers, but shit - if you own it, other people should respect that.
Join up, suckas.
"People demand freedom of speech to make up for the freedom of thought which they avoid."
- Soren Kierkegaard