Header image option missing from Multisite/Buddypress subsite

Hi guys,

I just set up a new subsite on my clean Multisite/BuddyPress installation. Now I had the main site looking nice, simple, but I want an easy life! I have BuddyPress Fun theme installed and added a custom header.

Now when I try to do the same (but change the header image) this option does not appear in my customisation. I noticed other themes had limited options on subsites too.

Is this deliberate or is there something awry?