Do you have a survey popup on your home page that automatically opens?
WCAG 2.0 bans all popup windows without explicit alert beforehand (WCAG 2.0 through Level AAA - 3.2.1 On Focus). New windows take the focus away from what the user is reading or doing. This is fine when the user has interacted with a piece of user interface and expects to get a new window, such as an options dialogue. The failure comes when pop-ups appear unexpectedly.