I want to draw an x-y-diagram with axis labels. Unfortunately the ylabel is misplaced. It looks as depending on the actual data. When the other data line in the sample below is used instead of the upper line, it looks better. How can I move the label to the left or (more desirable) how can I tell pgfplot to do it corectly?

% !TEX TS-program = pdflatex
% !TEX encoding = UTF-8 Unicode
\documentclass{scrartcl}
\usepackage[utf8]{inputenc} 
\usepackage{tikz}
\usepackage{pgfplots}
\begin{document}
 \begin{tikzpicture}
 \begin{axis}[width=13cm,height=8cm,
  xlabel={I in mA}, ylabel={U in mV}]
  \addplot[only marks,mark=star] coordinates {
%   (1.36, -0.0177) (45.38, 0.0273) (74.19, 0.0413)
  (100.88, 0.0533) (134.80, 0.0683) (195.27, 0.1073)
  };
 \end{axis}
 \end{tikzpicture}
\end{document}