Changing E-mail address

[moonissimo]

Hi,

I'm having a problem changing registered E-mail address. While I change it to another, I got a message saying like below.

Your eBay user id cannot be the same as your email address.

My ID is moonstar and an E-mail address that I want to register is moonstar@gmail.com. But eBay ID isn't an E-mail address

like moonstar@ebay.com or moonstar@gmail.com. It's just a combination of alphabet characters. So it's different from an E-mail address

that has @ and dot com. Why can't I use the same character set when an ID is different from an E-mail address?