I had a perfectly working implementation of Metabox on http://www.happyland.be. Just recently we updated everything on this site to use the latest version of every plugin. Now the switch values used as custom fields with WooCommerce products always save in the true state. If I go to a product that has a false value, it will have a true value after saving. I'm stumped to what could cause this.
The website has been moved from host too and in the process we exported and imported the custom meta table by hand. It looked like everything was allright.