Indeed remove your Key, As for your issue it is a known problem that newly created CD keys in origin don't work with the old account system for BF2 also Origin doesn't recognize old CD keys so if you have an older boxed retail copy of BF2 Origin wont detect the key as a legit key.
So you need to request support directly with origin staff and they will work through all the pogo accounts and stuff to correctly setup Battlefield you unfortunately won't find much support on these forums since they need to speak with you one on one.
There should be a ticket support system within Origin or even email support.
