check the status of your domain.
http://www.internic.net/whois.html
enter your domain name and check the STATUS. What you want to see is this:
Status: REGISTRAR-LOCK.
Registrar-lock means that your domain name is locked and can't be transferred until you manually "unlock" it. A lock keeps any transfer from taking place, so be sure to unlock the domain before you try to transfer it.
Some registrars automatically lock domain names, while others offer it as an option. Check with your registrar to be sure your domain name is safely locked away. There should not be a charge for this service.