title: QErrorMessage keeps on appearing
body: <p>I count some entries and want to emit a message, when the user has many entries, since it will be confusing.</p>
  
  <p>Nevertheless the other hand the user should have the option to disable this warning.</p>
  
  <p>That's why I wanted to use a <code>QErrorMessage</code>.</p>
  
  <p>But my <code>QErrorMessage</code> kept on appearing even when it should not (/when the checkbox is unchecked).</p>
  
  <p>This is the shortest code I wrote:</p>
  
  <pre><code>void checkNumber(int const &amp;n)
  {
      if(n &gt; CriticalNumber)
      {
          QErrorMessage msg(this);
          msg.showMessage("too much!");
      }
  }
  </code></pre>
  
  <p>Did I forget anything?</p>
  
  <p>The funny thing is, after you once unchecked the checkbox, it is unchecked in every next call...</p>
  
  <p>// edit:</p>
  
  <p>This error happens even when the <code>QErrorMessage</code> is a member of my class and not initialised in every call.</p>
  
  <p>// edit2:</p>
  
  <p>By now I am pretty sure, that this error only occurs, when I use <code>QString::arg</code>. I did not use this in the example code, since I thought this would make no difference. So the example should look like this:</p>
  
  <pre><code>void showError(int const &amp;n, QErrorMessage *msg)
  {
      msg-&gt;showMessage(tr("%1 is too big").arg(n));
  }
  </code></pre>
  
  <p><code>showError()</code> is called in the previous if-statement.</p>