It's a pain all right.
You can fix this if you are careful. Use the inspector to remove the vertical borders and the bottom borders of your fields. Draw a horizontal line all the way across the layout from the bottom left corner of Cue No. to the bottom right corner of the expanding field. Use the Inspector to set this field to slide up and resize enclosing part.
Now place vertical lines on your layout to serve as the borders of the sides of your fields. Start just below the header-body border and draw to one pixel below the body-footer border.
You can use the postiion tab in the inspector to adjust the vertical line length and postion of your line one pixel at a time. Once you have it extending that extra pixel, you can click units on the postion tab to change to centimeters or inches and specify a line length that falls between one pixel over the line and the exact number of pixels to fall just in side the footer.
Let's see if I can follow that. In fact, all the fields are transparent and borderless and those vertical borders you see are just that, but I'll do the think you mention. Same goes for the thick line going across the very bottom—that is as you would have me do it.
It's very picky. Even one pixel out of place will keep this from working and the horizontal line must be set to both slide up and to resize the enclosing part.
Okay, that's genius. It's imperfect—there are lines that now poke through the bottom of the layout, but I think I can bandage that up with a change in layout fill color. Well done, sir!