I am attempting the tutorial "part2" on http://doc.qt.nokia.com/4.7/gettingstartedqt.html. part1 successfully compiled and ran.

part2, however, is giving me an assertion fail when I exit it.
Qt Code: 
  1. File: f:\dd\vctools\crt_bld\self_x86\crt\src\dbgdel.cpp
  2. Line: 52
  3.  
  4. Expression: _BLOCK_TYPE_IS_VALID(pHead->nBlockUse)
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This is when I clicked the red X, click the Quit button (part of the tutorial), or Alt-F4.

Here is the tutorial code:
Qt Code: 
  1. #include <QtGui>
  2.  
  3. int main(int argv, char **args)
  4. {
  5.   QApplication app(argv, args);
  6.  
  7.   QTextEdit textEdit;
  8.   QPushButton quitButton("Quit");
  9.  
  10.   QObject::connect(&quitButton, SIGNAL(clicked()), qApp, SLOT(quit()));
  11.  
  12.   QVBoxLayout layout;
  13.   layout.addWidget(&textEdit);
  14.   layout.addWidget(&quitButton);
  15.  
  16.   QWidget window;
  17.   window.setLayout(&layout);
  18.  
  19.   window.show();
  20.  
  21.   return app.exec();
  22. }
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I've noticed that if the layout.addWidget(... lines are commented out, it does not produce an assertion error.

What could be causing this to happen?
Thanks.