either single-{custom}.php 404’s OR /taxonomy/ 404’s – custom post type and taxonomy permalinks

Well a few weeks on and my answer does seem to work – its interesting hearing people talk of using filters – as far as I am aware they are not necessary.

Whether /%product_cat% has any effect I am not sure so for my solution I’m leaving it out:

Product_Cat taxonomy should be:

'rewrite' => array( 'slug' => 'products','with_front' =>FALSE, 'hierarchical' => true )

Products Custom Post type needs to change to:
‘rewrite’ => array( ‘slug’ => ‘product’,’with_front’ => FALSE ),