Hi all
I am activating combobox at run time in following slot
Qt Code: 
  1. list_combobox.clear();
  2.     for(int i=0; i<obj_schedule_table->rowCount(); i++)
  3.     {
  4.         QWidget *widget1;
  5.         widget1 = obj_schedule_table->cellWidget(i,3);
  6.         QComboBox *combo = (QComboBox*)widget1->children().at(1);
  7.         combo->setEditable(false);
  8.         list_combobox<<combo;
  9.     }
  10.     signalMapper_selection = new QSignalMapper(this);
  11.     for(int i=0; i<list_combobox.size(); i++)
  12.     {
  13.         signalMapper_selection->setMapping(list_combobox.at(i), i);
  14.         connect(list_combobox.at(i), SIGNAL(activated(QString)), signalMapper_selection, SLOT (map()));
  15.         connect(signalMapper_selection, SIGNAL(mapped(int)), this, SLOT(set_item_combobox_type(int)));
  16.     }
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this slot is called on clicking a button "edit"

in remove_row slot i again connect these combobox to appropriate slots

Qt Code: 
  1. signalMapper_selection = new QSignalMapper(this);
  2.     QLineEdit *line_edit = (QLineEdit *)obj_schedule_table->cellWidget(index,0);
  3.     disconnect(list_combobox.at(index),0,0,0);
  4.     obj_schedule_table->removeRow(index);
  5.     list_combobox.removeAt(index);
  6.     for(int i=0; i<obj_schedule_table->rowCount(); i++)
  7.     {
  8.         signalMapper_selection->setMapping(list_combobox.at(i), i);
  9.         connect(list_combobox.at(i), SIGNAL(activated(QString)), signalMapper_selection, SLOT (map()));
  10.         connect(signalMapper_selection, SIGNAL(mapped(int)), this, SLOT(set_item_combobox_type(int)));
  11.     }
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When i remove a row and than activate a combobox in row below than that row it give segmantaion fault while working fine above the removed row.

Please help me what i am doing wrong.