Try and ask Alec ((post here http://www.rc-rp.com/f44-user-control-panel-accounts)) to check all the accounts made by your IP address. If there are some that you do not know of or do not want anymore you can request the deletion of any of those accounts ((here: http://www.rc-rp.com/f44-user-control-panel-accounts. ))
EDIT: No, i do not think you will be able to log in with any account from your IP address unless you delete some accounts