Cannot Create DK

Hello everyone, I need some help.

I have a lvl 61 on Onyxia but it will not let me make a lvl 55 Deathknight on Icecrown even though it says you need a lvl 55 on any realm?

Any ideas how I can fix this?

THank you
Ben

You must have a level 55 character on Icecrown or be a premium member.