Comment 1 for bug 42764

Other things are moving on the page too. Take this simple test case.

    .\" groff -t -ma4 -mm simple.tr >simple.ps
    .\"
    .DS
    foo
    .DE
    .DS
    bar
    .DE

The location of `bar' is vertically lower with 1.18 compared to 1.17.2.

Again, from the differences in the definition of DS, it looks like unit
changes for header and footer margins may be the cause.