One of the great things about moodle 2 for us uses is the: 'View courses without participation' permission
However we're noticing that the breadcrumb trail & navigation block alter drastically depending the users role in the course (ie. enrolled or not enrolled)

This does present quite a usability issue on the system as users have inconstant navigation through the site

Image 1.1: The bread crumb trail for a course the user is enrolled on
Image 1.2: The bread crumb trail for a course the user is not enrolled on - our preferred structure as it reflects where courses site in the site hierarchy.

The navigation block also presents some inconstancy here:
Image 2.1: When enrolled on a course the user can only see the courses they are enrolled on
Image 2.2: when not enrolled on a course the user get the option to navigate through all courses in addition to the 'my courses' option.

This issue is quite important to us and i'm sure others, particularly the breadcrumb issue.

Thanks for looking at this and let me know if I can provide more information.

Regards
Mark