I am getting non-existent child pages redirecting to another page with the same child part of the url instead of giving a 404 page not found error.
I've reproduced the problem on a clean installation with no plugins enabled and no configuration done:
http://www.pickituplater.co.uk/fred/prices/ exists and correctly shows Fred's prices page.
http://www.pickituplater.co.uk/bert/prices/ exists and correctly shows Bert's prices page.
http://www.pickituplater.co.uk/anythingelse/prices/ does not exist, but instead of getting a page not found it is instead redirecting to Fred's prices page.
How do I stop this unwanted behaviour?