I cannot login to Mac App Store, it says enter another apple id

I just purchased a new MacBook Pro Retina and after setting it up, I saw two updates for iPhoto and iMovie. I clicked the "Update All" button in the Mac App Store and the apps started downloading fine. However, I had to restart my system due to another installation. After restarting, the Mac App Store still says I ahve 2 pending updates but it doesn't let me do it. It constantly says "Enter another Apple ID" when I click on the "Update" button.