Hier die Lösung:

Code:
\makeatletter
\renewenvironment{cvlist}[1]{%
  \sbox{\@cvlistheading}{\cvlistheadingfont#1}%
  \begin{list}{}{%
      \renewcommand*{\makelabel}[1]{%
        \settowidth{\@tempdima}{\usebox{\@cvlistheading}}%
        \ifthenelse{\lengthtest{\@tempdima > 0pt}}{%
          \settowidth{\@tempdimb}{\cvlabelfont##1}%
          \ifthenelse{%
            \lengthtest{\@tempdima < \cvlabelwidth} \and
            \lengthtest{\@tempdimb = 0pt}}{%
            \parbox[b]{\cvlabelwidth}{%
              \vspace{\cvlabelskip}%
              \makebox[\cvlabelwidth][l]{%
                \box\@cvlistheading
              }%
              % nachfolgende Zeile wurde eingefuegt:
              \\*[0.5\baselineskip plus 1pt minus 1pt]%
            }%
          }{%
            \parbox[b]{0pt}{%
              \makebox[0pt][l]{\box\@cvlistheading}%
              \\*[0.5\baselineskip plus 1pt minus 1pt]%
            }%
          }%
        }{}%
        \cvlabelfont##1\hfill
      }%
      \setlength{\itemsep}{0ex}%
      \setlength{\parsep}{%
        0.5\baselineskip plus 1pt minus 1pt%
      }%
      \setlength{\topsep}{%
        1\baselineskip plus 2pt minus 2pt%
      }%
      \setlength{\partopsep}{0ex}%
      \setlength{\labelsep}{\cvlabelsep}%
      \setlength{\labelwidth}{\cvlabelwidth}%
      \setlength{\leftmargin}{\cvlabelwidth}%
      \addtolength{\leftmargin}{\cvlabelsep}%
    }%
}{%
  \end{list}%
}%
\makeatother