I'm sorry for the delay in responding. Thanks for the screenshots!
Got a really bring problem with custom header in the new Blaskan Theme: when I select to use a picture INSTEAD of the text header (so I deselect text header) the entire blog structure, I mean the entire page, becomes wider. Why?
So far, I have been unable to reproduce this issue in my testing, however I will look into this further for you. Could you provide me with the name of the browser(s) you've tested your site on? This would help me as I test further. Thanks!
in mobile theme (of course from a mobile browser) the text title blog is showed above the image header.
This is intentional. Our mobile theme, Minileven, was designed to display the site title above the custom header image, as you noticed.