Shared content fields not shown on registration page

Hi, I'm having a weird problem, would appreciate any guidance!

I have Content Profile module and Auto Assign Role, both latest Dev versions, on Drupal 6.8.

I created several content types for different user roles, then used Assign from Path feature
to create custom registration forms for each role. I added custom CCK fields to each content
profile, and they appear on the corresponding registration forms. That all works fine. But if I
try to add an existing ("shared") field from another content profile (some fields, like the user's
name, are logically the same, so I wanted to share them between profiles) - that field is not
shown on the new registration page - and it also disappears from the registration page of the
source content type! I checked permissions for each field, they are OK...

Is this a bug or am I missing something? Thanks in advance!