title: Custom TabControl display issues
body: <p>I've been writing a custom drawn tab control for a few days now and for the most part everything is pretty and it does an amazing job ... <strong>except when I use it on my Windows 10 computer (at run-time).</strong> </p>
  
  <p>I've gone back to the most basic few lines of code to trace the error and I can't for the life of me figure this out. </p>
  
  <p>Below is the only code being used, in a nutshell I'm designing a horizontal aligned tab control. </p>
  
  <pre><code>using System.Drawing;
  using System.Windows.Forms;
  
  namespace WindowsFormsApplication1.UI
  {
      class TabControlTest : TabControl
      {
          public TabControlTest()
          {
              Alignment = TabAlignment.Left;
              SizeMode = TabSizeMode.Fixed;
          }
      }
  }
  </code></pre>
  
  <p><img src="https://i.stack.imgur.com/HX0hV.png" alt="Design time form"></p>
  
  <p>I've simply added the custom tab control to the form, added a couple of group boxes for reference purposes and changed the background colour of the form to grey so you can clearly see the tab control. </p>
  
  <p>Now, <strong>at design time</strong> the 2 group boxes (1 in the tab control, 1 on the form) align perfectly. </p>
  
  <p>But at run-time I see a very different result.</p>
  
  <p><img src="https://i.stack.imgur.com/3qIND.png" alt="Form at run-time on my Windows 10 computer"></p>
  
  <p>As you can see the tab part of the control is now larger than it was at design time and the resulting change means the contexts of the tab have also moved. </p>
  
  <p>If I do this on a Windows 7 computer everything is displayed as it appears at design time, as it should!</p>
  
  <p>I've added ImageSize but it makes no difference. </p>
  
  <pre><code>ItemSize = new System.Drawing.Size(30, 150);
  </code></pre>
  
  <p>I've reinstalled VS on my (Win10) development machine. I'm at a loss to explain why and how to resolve this. </p>
  
  <p>Any/all help would be immensely appreciated.</p>