I'm using Xubuntu 13.04. There's a yellow update icon in my panel and when I click it, there is an unclickable grayed out options that says "There is 1 update available". When I click on the option to show updates, it says my computer is up to date.
I've tried sudo apt-get update, but it does not remove the message. What can I do to get this updated or at least remove it? I do not know what the update is because there is nothing telling me what it wants to update.