Parked Domain Removal Won't Show Up

Hey, i added a domain to my site (http://www.milliondesigns.net) and i want to add a new domain as an addondomain, on the same server (http://www.kirkevoldminilager.com).

At first it didnt work to add it to addon domains, so i decided to try Parke Domains.
After i did that both milliondesigns.net and kirkevoldminilager.com was the same site :S
My problem is that i cannot remove kirkevoldminilager.com from my parked domain, because of the dropdownlist is all blank, there is no domains in it!

Please help me!!