What capability do I use in Easy Blogging for header image upload?

HI. I've created custom menu items in Easy Blogging and all work except for the theme header image upload. It appears to be a capabilities issue, because if I turn off Easy Mode I can upload the image.

The attached screenshot #1 shows the different capabilities I've tried, but none work.

They all take me to my theme options page (screenshot #2) but when I click on Upload Image nothing happens. Turn off easy mode and it works.

So, I think I just need a different capability - but I don't know what it should be help. Any advice will be greatly appreciated. thanks