We recently updated a 255 install to 272. Things are working fine except we got an error when we first tried to add a new File Upload location under File Upload Preferences. The error was:
A Database Error Occurred
Error Number: 1062
Duplicate entry '4-5' for key 'PRIMARY'
INSERT INTO exp_upload_no_access
(upload_id
, upload_loc
, member_group
) VALUES (4, 'cp', '5')
Filename: controllers/cp/content_files.php
Line Number: 2338
Since that time, we have not been able to replicate this and it seems adding, editing and deleting locations is working ok. Is this something worth worrying about?