Sorry, If I am doing something very stupid, but I can't seem to activate OD+

I just bought the program, downloaded it and installed it. I restarted, and then it asked me to put in the email/registration. I stuck in my email and copied the code from the email.

"The product activation was unsuccessful" Nothing more specific than that.
I tried several other email addresses, no luck.

I have uninstalled the free object dock first. Is there anything else I need to do?