Harty on "Google analytics - wrong website showing"

Hi. I'm using the GA plugin - everything is up to date. I have a few websites, we'll call them sites A and B.
Despite checking everything many times, I can't fathom why site A is showing traffic from site B in the Dashboard using the GA Summary panel.
I have checked the obvious, i.e., Site A is selected in the GA control panel as the one to refer to (not site B).
Any ideas?
Cheers,