u can reset your admin username/password to default (admin/admin):
in phpmyadmin chose your 4images database, go to "SQL" and execute this:
INSERT INTO 4images_users (user_id, user_level, user_name, user_password, user_email, user_showemail, user_allowemails, user_invisible, user_joindate, user_activationkey, user_lastaction, user_location, user_lastvisit, user_comments, user_homepage, user_icq) VALUES (1,9,'admin','21232f297a57a5a743894a0e4a801fc3','admin@yourdomain.com',1,1,0,1016023608,'1e3457c0b2052a9633b886fd75ef91e0',1016023608,'',0,0,'','');