Memory problems, please help!

I have an application that has given me no problems for the last week... I boot it up this morning and all of a sudden I am getting unhandled exceptions that point to a memory leak of some sort... I have been trying to figure out why and fix it, but have come up empty handed.

Code:

---

void WInterface::toggleCueingSize()
{
  QPushButton *clickedButton = qobject_cast<QPushButton *>(sender());
  if (clickedButton != 0)
  {
    std::string compareString = clickedButton->objectName().toStdString();
    if (compareString.compare("bannerSensorSelectButton")==0)
    {
      ui->wBannerSensorDisplay->show();
      ui->wSensorOnlyDisplay->hide();
      ui->viewModeSettings->hide();
    }
    else if (compareString.compare("sensorOnlySelectButton")==0)
    {
      ui->wBannerSensorDisplay->hide();
      ui->wSensorOnlyDisplay->show();
      ui->viewModeSettings->hide();
    }
    else if (ui->weaponsSensorOnlyDisplay->isHidden())
    {
      ui->wBannerSensorDisplay->hide();
      ui->wSensorOnlyDisplay->show();
    }
    else
    {
      ui->wBannerSensorDisplay->show();
      ui->wSensorOnlyDisplay->hide();
    }
  }
}

---

this code gives me this error:

HEAP[PresQT.exe]: Invalid Address specified to RtlFreeHeap( 003F0000, 02C45BA0 )
Unhandled exception at 0x7c90120e in PresQT.exe: User breakpoint.

and it is crashing somewhere in free.c

I have commented out the the QPushButton assignment along with the string and the 2 conditional statements that involve the string, and it works fine... so it has something to do with the dynamic cast and the string assignment, but i dont know why or where the problem is...

anyone have any idea? help is greatly appreciated!

found the problem... apparently getObject() is an unstable function... switched to text() and now have no problems