title: SWT Composite needs pack() in 3.6.1
body: <p>My wizard isn't rendering correctly in Eclipse 3.6.1. It's leading me to wonder: when does one have to use Composite.pack()? Some SWT examples have it, and some don't.</p>
  
  <p>How my wizard pages renders depends on the target platform. If I run my plugins in 3.5.2, they render correctly as soon as I open them. But in 3.6.1, their contents areas are blank when they first one. The pages use GridLayout.</p>
  
  <p>If I use the mouse to resize the wizard dialog, it immediately renders just fine.
  If I call pack() on the control that I pass to DialogPage.setControl(), the page renders, but it's not quite wide enough. A subsequent resize fixes the width.</p>
  
  <p>Can someone shed some light? Is there a general rule for when to use pack()? </p>
  
  <p>(Tagged with Swing because experts there may have answers as well as SWTers.)</p>