Can't log in to my site after I moved it to a new server.

I moved my website to a new server to redesign it, but after doing it I get this message when trying to log in to the admin area.

“ERROR: Cookies are blocked due to unexpected output. For help, please see this documentation or try the support forums.”

I checked the database and all usernames and passwords are correct. I called godaddy (who is my hosting provider) and they checked the installation and all setting and can’t find anything wrong. But they can’t help when it comes to specific problems like this.

Does any one know what might be the problem?

Thanks.