I've had issue a couple of times now, where if SP hiccups, times out, or crashes, the Toolbar button complains that SP isn't the latest version and needs to be updated. Restarting the browser doesn't fix the issue, as Chrome is still running in the notification tray.
The fix is quit the Chrome system tray icon as well, or switch off "Let Chrome run in the background." Even though no Chrome apps or extensions are noticeably active in the background, as long as a Chrome task is running, the toolbar icon says SP needs to be upgraded.
This has happened since upgrading to Chrome 33.0.1750. It's technically not a bug in SP or Chrome, just a quirk.