If you are unable to add items to your Magento shopping cart try one of the following resolutions. This is generally an issue with the cookies.
1. Remove session cookie parameters
Quite a drastic measure, so make sure to comment out, rather than delete:
Go to: Magento Folder/app/code/core/Mage/Core/Model/Session/Abstract/Varien.php
and comment out the following that starts at about line 87 as you see below.
// session cookie params
$cookieParams = array(
'lifetime' => $cookie->getLifetime(),
'path' => $cookie->getPath(),
'domain' => $cookie->getConfigDomain(),
'secure' => $cookie->isSecure(),
'httponly' => $cookie->getHttponly()
);
