Not sure what you are referring to Dan,
You are commenting on the 'large' gap at the top of the screen but saying it looks fine on Gourmet, and yet on those screenshots, the gap at the top looks far bigger on Gourmet than on the others?
For reference (and because I've just changed this on my own site for various enforced design issues relating to the custom theme): The top margin appears to be set within the module.js of the grid format (Note - all the usual advice about editing files and potential effects when later upgrading apply here!)
/* This is added here as not editing and JS is on to move the content from
below the grid icons and into the shade box. */
var content = document.getElementById('gridshadebox_content');
content.style.position = 'absolute';
content.style.width = '90%';
content.style.top = 'YOUR_NEW_VALUE_HEREpx';
content.style.left = '5%';
//content.style.marginLeft = '-400px';
content.style.zIndex = '1';
};