Im using a wfcart in my WordPress site but for some reason on certain pages WordPress drops the session I'm wondering if there is a way to enable sessions in WordPress 3?
If you need to manually enable the session globally, use this in your functions.php (I included a line for manually setting a session variable as an example, not required):
and if you wanted to manually clear the session on an event (like logging out):
As an addition to Somatic's reply, note that sessions can prevent you from scaling when misconfigured.
Specifically, if your site spans more than one server, be sure to use one of the built-in Memcached save handlers from pecl, or an SQL-based session handler. And if you opt for an SQL handler written in php, be sure to use row-locking if your app involves any Ajax.
Not doing so and sticking to the filesystem handler, you may end up losing sessions based on which server gets hit by end users.