vertical spacing in leadsheet with text between staffs

[Jürgen Spiekermann]

> I'm not top posting.
Hello, 
the following example shows two staffs with a Text between the staff:
\version "2.16.2"
\paper {
        #(set-paper-size "a5")
    print-page-number = ##f
        ragged-right = ##f
    ragged-last-bottom = ##t
    ragged-bottom = ##t
}
\layout { 
        indent = 0.0\cm 
}
        <<
        \new ChordNames{ \germanChords \chordmode{ \germanChords f1 c1 c1 f1} }
        \relative c' {
                \time 4/4
                \key f \major
                f4 f f f g e c2 g'4 g f g a2 f2
        } 
        \addlyrics { \set stanza = #"1." Chris -- tus lädt uns al -- le ein, wir
sind sei -- ne Gäs -- te. }
        >>
        \markup{\bold "Zwischenvers"}
        <<
        \new ChordNames{ \germanChords \chordmode{ \germanChords g1:7 c1 g1:7 
c1  } }
        \relative c' {
                \time 4/4
                \key f \major
                g'4 g a b c2 a g4 a g f e2 d \bar "|."
        } 
        \addlyrics { \set stanza = #"1.-2." Seg -- ne, was wir ge -- ben, seg 
-- ne
un -- ser Le -- ben! }
>>
        


        

The second staff is printed with huge space between Text and staff.
Ist this a bug? It does not happen without \addlyrics

Any help is appreciated