header showing twice bellow each other on Explorer 8

Header is showing twice, bellow each other, on Explorer 8. I know that to solving this problem is upgrading to explorer 9 or later but what with users that are not willing or capable of doing this? I am running Arturo theme and header is exactly 935×160 px as the recommended size is in the header settings. https://listeningcentre.com/wordpress
Anybody can help?