I have this code that setted when login check is fine:
if((isset($_POST[\"remember_me\"]))&&($_POST[\"remember_me\"]==1)) { setcookie(\'email
Check in your browser for the directory where the cookie operates. And unset it by specify the path the cookie have. Like in the example if the cookie directory is /aforum/
/aforum/
setcookie ("email","",time()-1,"/aforum/","http:// yourdomain.com");