I will change the address on cex.io to this one "1HdK3k1LWG429jADbu9GXTszWmGGz9uVdX" will provide a screenshot of my wallet and cex.io and sign it with that message.
AFAIK cex.io does not allow you to sign messages. Did you ever use a programm as wellet and posted an address that is controlled by that wallet?
the only wallet I've used is blockchains, never used a wallet software.
Blockchain allows you to export your private keys.
I still don't get this trading card thing or the whole bitcrystals concept ,maybe because I'm not a game. I will be buying my first trading card tomorrow