Hi kmeronuk – thanks for the suggestion. I can confirm that clicking the “Check Again” button on the main WP updates page (eg http://www.example.com/geneve/wp-admin/update-core.php) solves the problem on two of my sites for me too.
However, I clicked on the “solved” button on your reply too soon, as there are still 2 other sites still with the same old problem, so still not 100% solved!
:-/