Running the code below, hold down LMB in the left cell, then drag the mouse cursor to the right cell.
The right cell is now selected, but shouldn't be.

// --------------------------------------------------------------
#include <QtGui>

int main( int argc, char * argv[] )
{
QApplication app( argc, argv );
QTableWidget table( 1, 2 );
table.setSelectionMode( QAbstractItemView::NoSelection );
table.setCellWidget( 0, 1, new QCheckBox() );
table.show();
return app.exec();
}
// --------------------------------------------------------------