Header image won’t appear… except in mobile view?!

Hello all,

first post and first question.

I have a blog deadl.ie and everything was going well until I updated my header last week.

I uploaded a new .jpg that was 780×95 as per Freshy requirements, deleted the old and tried to place the new one as it. I go to header, upload the image, wait and then click ‘see what it looks like’, but nothing. It’s been like this for three days.

However when viewed on a mobile device using the mobile view, the header is fine.

Even when I try to upload a set-themed header (like the one that was in place when I first started using freshy), I still get a blank square.

Is this perhaps a CSS problem? Or am I missing something glaringly obvious???

The image should be this:
https://deadl.files.wordpress.com/2010/05/cropped-deadl2.jpg

Thanks in advance!

Sean