Serial number entered is invalid
I'm getting this error when I try to enter my serial number.
"ERROR: The serial number you entered is invalid. Double-check that you entered the serial number correctly."
I have completely removed the website from the server and reloaded it with a fresh NON-CMS site. Then tried again to do the CMS install, following the GSG word for word. Everything looks like it's working and then I can't register the serial number. I know it's a good number, I've used it before. And have cut and pasted it as well as hand typed it in, to no avail.