Click on a “more info”/”reviews” link. It will launch a large dialog with detailed information on the location you’re considering.

Now, while this dialog is up, position the cursor outside of it and scroll the mouse wheel. The map zooms. The dialog goes off-screen. Chaos ensues if you zoom out to get it back (though panning generally works). You can even get part of the map to extend outside of the mapping window if you keep zooming.

Tested in Firefox and IE. It seems worse in Firefox.

It’s just cosmetic, so it isn’t that serious.