p.s., ptarver: nice apropos link! 🙂
I have a similar problem. The notification tells me 1 update is required, but the updates screen tells me I have everything up to date. A plugin I am using called Wordfence tells me a plugin “” needs updating, that I have version 3.7.4 and that the update is “critical.” But since it doesn’t tell me what the plugin is (“”) is all it shows, I cannot tell what to do. The “Click here to update now” button (when moused over) shows update-core.php, and takes me to the WordPress Updates part of the Dashboard (where, again, it tells me everything is up to date). Note, this behavior occurred before activating the Wordfence plugin.