Ebay and Wireless encription

Hi all newbie here wanting some help! I just installed a wireless system with a belkin USB adapter and a BT buisness hub. I can connect to my acccount in ebay from my laptop ethernet connected to the hub but when i try to do it wirelessly it cuts the connection. This is only when I log in. If I'm not logged in it works fine. I can look for thgings etc without problems. I am using WEP64 could that be the problem and it needs 128?
Digger