Hi Pylon,
Just updating this topic as we’re corresponding via e-mail too, can you send through login details so I can see why the menu is not appearing in the latest Custom Fields, please note that the menu recently changed to ‘Attributes’ under Products > Attributes within the WordPress Administration.
It’s very likely in the most recent Plugin update for Custom Fields that the mapping to Product Importer has changed, making sure all the Plugins are up to date (including Custom Fields) will reduce the chance of import/merge errors. Flick through an e-mail if you’re still stuck. 🙂
