Page not found when using {% paginate %} - but only sometimes.

[jlabs]

Tearing my hair out today trying to work out why I would get to a "Page not found" page when going to any page other than page 1 in a paginated set of data.

I've just discovered that turning "Use a Catch All page template" off fixes this issue (not sure on the implications on the rest of the site - will confer with the other devs) ... but ... it doesn't explain why this only occurs on a second level Single entry e.g. /news/p2 gives "Page cannot be found" error, but /play/news/p2 (using the exact same template code) will display page 2 of the paginated results.