Unexpected spaces in Browse mode

[Wickerman]

I have a layout for a chart with three parts: Leading Grand Summary, and 2 sub--summaries. The data and chart are displaying ok.

I've written a script to display the layout in a new window, with a 'Resize to Fit' window step included.

But when I trigger the script, I'm getting a window that stretches the entire height of my screen, with a huge blank space for the bottom half. Also, there's a mysterious grey band showing below the last data line. I note that this grey band gets thicker if I increase the size of the first sub-summary part.

I'd kind of like to get rid of the grey band - - and the window really needs to be a little 'shrunk to fit' the data. Any guess what I've got wrong? See attached images of the layout mode and display mode.

[Wickerman]

As an added note, I am using 'List View' when I get this behavior. If I et the layout to default to 'Form View' then the window sizing behaves properly - - but of course I don't get the sub-summary fields / data displaying then unless I go to Preview mode.

thanks for any help.