Bought the book yesterday...

I am trying to create a panel page.

I have:
Name: member_profile
Administrative title: Member Profile
Path: node/%

Advanced setings for: Disable Drupal blocks/regions, CSS ID:, CSS code:, have been left empty.
As instructed...

There is no setting for "Define a context:" which I assume will appear when the form is submitted.

However, when submitting, I get:
Error: That path is already in used. This system cannot override existing paths.

I tried naming the page "profile" with the same results.