Version 3.1.3 doesn't detect updates

Hi there,

I was recently asked to update someone’s WP site. They’re using version 3.1.3 and on the update page it says “You have the latest version of WordPress” which clearly can’t be true.

A BWS Updater plugin was installed but even after deactivating this, WP continues not to detect updates. It’s a german installation in case that could matter.

It would be great to find a way to update this version!

Thank you!