Marketpress themes not visible unless SuperAdmin?

I am building theme "skins" for my network using the built-in marketpress option to choose themes. I created a css file (with the necessary comment on the beginning of the file), uploaded it to marketpress-includes/themes and as expected, when I visited the settings page for marketpress (/wp-admin/edit.php?post_type=product&page=marketpress&tab=presentation) it was there, ready to be selected and functioning properly.
BUT when I tried to select the theme using anadmin account and not a superadmin, the new theme was not present on the dropdown and the only items present were the marketpress original ones. I switched back to superadmin and it was there.

Has anyone else noticed this?