6 to 7 upgrade brings Failed: PDOException: SQLSTATE[23000]: Integrity constraint violation: 1062 Duplicate entry

I have a couple of drupal sites up and running and I have not had to pay much attention to the databases until I tried to do an core upgrade from D6 to D7.

Here's the first part of the error message I received running update.php after a GUI/FTP replacement of version 6 files with version 7 files:

system module
Update #7007

Failed: PDOException: SQLSTATE[23000]: Integrity constraint violation: 1062 Duplicate entry '1-use exclude node title' for key 1: INSERT INTO {role_permission} (rid, permission) VALUES (:db_insert_placeholder_0, :db_insert_placeholder_1), (:db_insert_placeholder_2, :db_insert_placeholder_3), (:db_insert_placeholder_4, :db_insert_placeholder_5), (:db_insert_placeholder_6, :db_insert_placeholder_7), (:db_insert_placeholder_8, :db_insert_placeholder_9),

The full error message is here.

Can anyone suggest a course of action to remediate this problem?

Thanks!