P: Bug in Book module (interface bug)

In the book module one can enter different fillings (whited border) for each side of the foto cell (left, right, up, down). However, when I later enter that cell again, Lightroom checks all the small boxes to connect each of the fillings. When I then uncheck any of the boxes, Lightroom resets all fillings to one of the values.

Very annoying, please fix this.