It seems that some users of the PayPal plugin version 0.4.0 are having trouble adding new products to the database. This issue cannot be duplicated in development or testing environments, so there's no firm fix yet. However, version 0.4.1 of the plugin includes a global "debug" option which will cause a variety of messages to be logged to the site's error.log file where they can be viewed with the log viewer. Hopefully this will help troubleshoot the issue. Version 0.4.1 is available now for download at www.glfusion.org.