Jpeg header doesn't display on small screens

Hi Mick,

I’m trying to change add my logo in adaptive-flat but experiencing all sorts of issues. The jpeg ones don’t display on small screens and change collour (do display and keep collour when using other theme). PNG does display and keep collour but highly pixilates on big screens. Never had this issue with other themes before. Can you help out? Do love your theme and would like to start using it. Also keen for some customizations integrating slider on home page in later stage. Are you planning for that at all?

Thanks for your help!
Djoeke