I asked my host to look in my Control Panel and see if anything was amiss, there was, here is their reply:
'Your banner image is not displaying because you have enabled Hotlink Protection within your account, but appear to have not added the savanamotors.co.uk domain to the list of domains excluded from this - I have now added this for you, and your banner.jpg image is loading correctly.'
My fault after all, but then most thing I guess are 'user error'.