Thought I'd report this here (pls direct somewhere better if needed). This was resolved by tagging a new update.
I maintain the plugin events manager and when updating as usual everything seems ok but it seems that nobody's receiving update notifications.
Happened with 3.2 or 3.1.x
Went a little further and checked wp_update_plugins() and from the looks of it, the blog is sending the right plugin version info, api.wordpress.org wasn't sending back an updated version.
Previous version was 4.0.83, I updated it to 4.0.9 on Monday and still no update, so I've tried tagging again to 4.1 just now and fortunately it worked.