Strange layering with Team popup

Hi Nur! Could you please peek at http://paulmorrisoncolours.com/staff? I can't figure out why the very first person's popup (Paul, the owner, of course) gets strangely hidden by following Team thumbnails when scrolling with the popup open. The first popup is also covered by the menu bar which makes the closing X a bit tricky to locate. All the following team members' popups appear normally with the rest of the page elements beneath them. Thanks for any insight and ideas how I can correct this. And thanks for the great plugin and responsive support!