Thanks for the screenshots - that's a lot of help.

I've reproduced this here by carefully docking / undocking the main graph area "just right". It looks like you're docked to a spot that only resizes against the top edge, not the top and bottom edge (there is a condition where you'd *want* to dock like this).

If you undock the graphs (double-click on the blue "caption" bar above the graphs). This will leave all the graphs undocked. Now, drag the undocked window back into the user interface. As you drag, you'll see the docking lines show the area where the graphs will be docked. There are a couple of positions that look similar, but are differentiated by where the bottom "docking line" shows. Make sure you dock on the one where the line is bumped right against the bottom edge. There's another docking position where it's a bit higher (the "don't fill the area, instead use my specified height" position).

I've attached an image that should illustrate where you want to dock. All the docking lines should be against all edges. On any edges where you're not docking against the edge fully, the graphs won't be resized when you resize that edge of PingPlotter.

Hopefully, that should take care of this problem. Let us know!

- Pete