For some reason, when I open the "Zoom" dialog box and select the "Text width" radio button, Page Layout view mode ceases to be capable of keeping track of scroll position between minimizing and restoring the window. However, if I just click once on the down triangle in the "Percent" box after clicking on the "Text width" radio button, reducing the magnification by one percent, Page Layout view mode magically becomes able to keep track of scroll locations.

So I suppose I can't just rely on "Text width". I'm going to have to pop the zoom percentile down by one percent. Another odd Microsloth bug...