I have built a grapher-based tool, that allows me to distinguish between multiple types of node by using shapes. When I highlight rectangular nodes, all is well. But I have "roundtangle" nodes, and when I pass the mouse over them, instead of seeing a box around them, or a highlight outline around the roundtangle, McCLIM gives me THREE rectangles, one around the body of the node, and one each around the semi-circles on the end.
You probably want to use :single-box T in with-output-as-presentation.
Paul