rehearsal mark staff-padding

[Andrew Hawryluk]

Why is only the first mark shifted upward? Is it a bug in the program
or the user? :)

Andrew

\version "2.11.42"
\paper {ragged-right = ##t}
\relative c' {
        c c c c
        \once \override Score.RehearsalMark #'padding = #5
        \mark \markup Markup
        c c c c
        \once \override Score.RehearsalMark #'staff-padding = #5
        \mark \markup Markup
        c c c c
}