Using the free theme sometime may result of customer not logged in problem issue. To resolve this issue we need to put the for key field in the login form.
In app/design/frontend/default/…/template/persistent/customer/form/login.phtml , around line 41 should look like
<form action="<?php echo $this->getPostActionUrl() ?>" method="post" id="login-form">
<?php echo $this->getBlockHtml('formkey'); ?>
If the code is not seen then add it then customer login works