PSTricks and \pscustom

PSTricks and \pscustom

Consider the following example:
Code
% pdflatex -shell-escape maj1999.tex

\documentclass{article}

\usepackage{auto-pst-pdf,pstricks-add}

\begin{document}

\begin{pspicture}(-4,-4)(4,1)
  \pscustom[fillstyle=solid,fillcolor=lightgray]{%
    \psarc(0,0){3.53}{180}{360}
    \psarc(-3.74,0){0.21}{0}{180}
    \psarc(0,0){3.95}{180}{360}
    \psarc(3.74,0){0.21}{0}{180}
  }
\end{pspicture}

\end{document}
Output

Question
How do I make PSTricks fill only the enclosed area (the horizontal line isn't there if you remove \pscustom)?