Guys, I strove to circumvent the issue by placing one checkbox instead of two radios. It's like an ufo... Now the program works but I get 'core dumped' after having exited the application. So I assume there is a problem with destruction...

Qt Code: 
  1. (gdb) backtrace
  2. #0  0xffffe410 in __kernel_vsyscall ()
  3. #1  0xb720a770 in raise () from /lib/tls/i686/cmov/libc.so.6
  4. #2  0xb720bef3 in abort () from /lib/tls/i686/cmov/libc.so.6
  5. #3  0xb723fd0b in __fsetlocking () from /lib/tls/i686/cmov/libc.so.6
  6. #4  0xb72478bd in mallopt () from /lib/tls/i686/cmov/libc.so.6
  7. #5  0xb7247a44 in free () from /lib/tls/i686/cmov/libc.so.6
  8. #6  0xb7536e5d in QHashData::freeNode (this=0x8112498, node=0x8124af8)
  9.     at tools/qhash.cpp:132
  10. #7  0xb7991abd in QHash<unsigned long, QWidget*>::remove (this=0x8108d30,
  11.     akey=@0x812498c)
  12.     at ../../include/QtCore/../../src/corelib/tools/qhash.h:450
  13. #8  0xb7982eff in QWidgetPrivate::setWinId (this=0x8124950, id=0)
  14.     at kernel/qwidget.cpp:1180
  15. #9  0xb79b8dcc in QWidget::destroy (this=0x81248b8, destroyWindow=true,
  16.     destroySubWindows=true) at kernel/qwidget_x11.cpp:782
  17. #10 0xb798866c in ~QWidget (this=0x81248b8) at kernel/qwidget.cpp:1162
  18. #11 0xb7bd7ef1 in ~QAbstractButton (this=0x81248b8)
  19.     at widgets/qabstractbutton.cpp:572
  20. #12 0xb7c846e5 in ~QToolButton (this=0x81248b8) at widgets/qtoolbutton.cpp:347
  21. #13 0xb75d4ea1 in QObjectPrivate::deleteChildren (this=0x8123978)
  22.     at kernel/qobject.cpp:1823
  23. #14 0xb7988649 in ~QWidget (this=0x8123938) at kernel/qwidget.cpp:1158
  24. #15 0xb7c7e844 in ~QToolBar (this=0x8123938) at widgets/qtoolbar.cpp:472
  25. ---Type <return> to continue, or q <return> to quit---
  26. #16 0xb75d4ea1 in QObjectPrivate::deleteChildren (this=0x810b300)
  27.     at kernel/qobject.cpp:1823
  28. #17 0xb7988649 in ~QWidget (this=0xbf85ebf0) at kernel/qwidget.cpp:1158
  29. #18 0xb7c30c21 in ~QMainWindow (this=0xbf85ebf0) at widgets/qmainwindow.cpp:292
  30. #19 0x080527ca in main ()
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The code was altered in mymvc.h:
Qt Code: 
  2. 	QLabel* label;
  3. 	QCheckBox* checkOne;
  4. 	bool caseSensitive;
  5. };
  6.  
  7. #endif
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and in mymvc.cpp:
Qt Code: 
  1. label = new QLabel(tr("Enter a character string below"));
  2. checkOne = new QCheckBox(tr("Case Sensitive"));
  3. checkOne->setChecked(true);
  4. caseSensitive = true;
  5. qvb = new QGridLayout();
  6. 	connect(checkOne,SIGNAL(toggled(bool)),this,SLOT(setCaseSensitive(bool)));
  7. connect(qcb,SIGNAL(currentIndexChanged(int)),le,SLOT(clear()));
  8. connect(qcb,SIGNAL(currentIndexChanged(int)),qtv,SLOT(filter()));
  9. connect(le,SIGNAL(textChanged(const QString &)),qtv,SLOT(filter()));
  10.    connect(model,SIGNAL(fromTVtoVM(int)),this,SIGNAL(doubleClickInTreeView(int)));
  11.  
  12. qvb->addWidget(label,0,0,1,2);
  13. qvb->addWidget(le,1,0);
  14. qvb->addWidget(checkOne,1,1);
  15. qvb->addWidget(qcb,2,0,1,2);
  16. qvb->addWidget(qtv,3,0,1,2);
  17.    setLayout(qvb);
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