Just to add to the conflict list: Formidable Forms (lite or Pro).
With WPSP Pro active, the following message would appear whenever trying to access any of the FF items other than the Forms item.
You do not have sufficient permissions to access this page.
Deactivate WPSP Pro and all access is restored to normal.
However, after updating to version 0.3 of WPSP Pro, all is fine again 🙂