Unable to save customer name to mysql database in magento

Here is my code:

if ($user->isLoggedIn()) {

            $userinfo = $user->getCustomer();
            $userid = $userinfo->getId();
            $username = $userinfo->getEmail();
            $userfullname = $userinfo->getName();
            Mage::log(
                    "{$userid},{$username},{$userfullname}\n",
                    null,
                    'product-updates.log'
                );
            $up_id = intval($userinfo->getId().$product->getId()."");
            $data = array(
                        'click_time' => date("Y-m-d H:i:s"),
                        'product_id' => $product->getId(),
                        'product_name' => $product->getName(),
                        'product_category' => $category,
                        'product_value' => $product->getPrice(),
                        'user_id' => $userid,
                        'username' => $username,
                        'fullname' => $userfullname,
                        'firstname' => $userinfo->getFirstname(),
                        'middlename' => $userinfo->getMiddlename(),
                        'lastname' => $userinfo->getLastname(),
                        'register_time' => $userinfo->getCreatedAt(),
                        'up_id' => $up_id
                    );
            $model = Mage::getModel('modulename/modelName')->load($up_id,'up_id')->addData($data);
            try {
                $insertId = $model->save()->getId();
            } catch (Exception $e){
            }
}

Points:

-> product-updates.log file logs everything correctly with username (email) and full name of the customer.

-> on saving to database, product_id , and all fields successfully save except for customer name, customer middle, first and last name and register_time.

-> No errors in system.log, no exceptions in exception.log

-> Logs are enabled and cache is disabled.

Problem:

So problem is that I am not able to save customer name, even though it is being displayed in the product-log file correctly. Also there are no syntax errors or any other error because other fields are getting saved to the database.

Edit: My database structure:

username    varchar(200)
fullname    varchar(200)
firstname   varchar(200)
middlename  varchar(200)
lastname    varchar(200)