Klasse scrlttr2, LetterOption visualize, Fehler bei Darstellung des Feldes location

\listfiles
 
\documentclass[parskip=half]{scrlttr2}
 
\usepackage[german]{babel}
\usepackage[ansinew]{inputenc}
\usepackage{dcolumn}
 
\LoadLetterOption{visualize}
\showfields{head,address,location,refline,foot}
 
\begin{document}
  \begin{letter}{Name\\Anschrift}
    \setkomavar{location}{}%
    \opening{\null}%
    Variable \textit{location} ohne Inhalt:\par%
    \begin{tabular}{r@{~}c@{~}D{.}{.}{-1}}%
      \bfseries Pseudolänge  &   & \mathbf{Wert}                 \\%
      toaddrheight           & = & \the\useplength{toaddrheight} \\%
      locheight              & = & \the\useplength{locheight}    \\%
    \end{tabular}%
    \par {\small Ergebnis: Die Rahmen der Felder \textit{address}
    und \textit{location} sind gleich hoch.}%
    \closing{\null}%
  \end{letter}
  \begin{letter}{Name\\Anschrift}
    \setkomavar{location}{Location}%
    \opening{\null}%
    Variable \textit{location} mit Inhalt:\par%
    \begin{tabular}{r@{~}c@{~}D{.}{.}{-1}}%
      \bfseries Pseudolänge  &   & \mathbf{Wert}                 \\%
      toaddrheight           & = & \the\useplength{toaddrheight} \\%
      locheight              & = & \the\useplength{locheight}    \\%
    \end{tabular}%
    \par {\small Ergebnis: Die Rahmen der Felder \textit{address}
    und \textit{location} sind unterschiedlich hoch.}%
    \closing{\null}%
  \end{letter}
\end{document}

   scrlttr2.cls  2010/06/17 v3.06   KOMA-Script document class (letter)
   scrkbase.sty  2010/06/17 v3.06   KOMA-Script package (KOMA-Script-dependent basics and keyval usage)
    scrbase.sty  2010/06/17 v3.06   KOMA-Script package (KOMA-Script-independent basics and keyval usage)
     keyval.sty  1999/03/16 v1.13   key=value parser (DPC)
   scrlfile.sty  2009/03/25 v3.03   KOMA-Script package (loading files)
scrsize12pt.clo  2010/06/17 v3.06   KOMA-Script font size class option (12pt)
   typearea.sty  2010/06/17 v3.06   KOMA-Script package (type area)
        DIN.lco  2010/06/17 v3.06   KOMA-Script letter-class-option
      babel.sty  2008/07/06 v3.8l   The Babel package
    bblopts.cfg  2006/07/31 v1.0    MiKTeX 'babel' configuration
    germanb.ldf  2008/06/01 v2.6m   German support from the babel system
   inputenc.sty  2008/03/30 v1.1d   Input encoding file
    ansinew.def  2008/03/30 v1.1d   Input encoding file
    dcolumn.sty  2001/05/28 v1.06   decimal alignment package (DPC)
      array.sty  2008/09/09 v2.4c   Tabular extension package (FMi)
  visualize.lco  2010/06/17 v3.06   KOMA-Script letter-class-option
    eso-pic.sty  2010/06/08 v2.0b   eso-pic (RN)
   atbegshi.sty  2010/03/25 v1.12   At begin shipout hook (HO)
  infwarerr.sty  2010/04/08 v1.3    Providing info/warning/message (HO)
    ltxcmds.sty  2010/04/26 v1.7    LaTeX kernel commands for general use (HO)
      ifpdf.sty  2010/01/28 v2.1    Provides the ifpdf switch (HO)
     xcolor.sty  2007/01/21 v2.11   LaTeX color extensions (UK)
      color.cfg  2007/01/18 v1.5    color configuration of teTeX/TeXLive
     pdftex.def  2010/02/14 v0.04n  Graphics/color for pdfTeX
   graphicx.sty  1999/02/16 v1.0f   Enhanced LaTeX Graphics (DPC,SPQR)
   graphics.sty  2009/02/05 v1.0o   Standard LaTeX Graphics (DPC,SPQR)
       trig.sty  1999/03/16 v1.09   sin cos tan (DPC)
   graphics.cfg  2007/01/18 v1.5    graphics configuration of teTeX/TeXLive
   supp-pdf.tex