On registration, required taxonomy fields are not enforced for node profile node

Issue Summary

I'm using nodeprofile, integrated with the user registration page.
The user fills in the fields for the embedded node form, and then the user details.

However, it seems that when the form is submitted, any 'required' taxonomy fields in the node form, are not enforced.
ie, if a field is required, but left blank, the node is still submitted, even though the field is required.

Regards
Alan