QGeoMapRouteObject not displaying route properly on map on S60 devices

Calculated a route between 2 points and tried to display it using the QGeoMapRouteObject but the route is displayed in a very patchy way.

Eg Code :
void MapWidget::showRoute( QGeoRoute route )
{
m_route = new QGeoMapRouteObject;
m_route->setPen(QPen(Qt::blue, 2.0));
m_route->setRoute( route );

m_map->addMapObject( m_route );
}

Tried it on both S60 Devices [N97 and 5800] and Symbian^3 device [C7]. While S^3 devices displayed it properly, both S60 devices failed to display properly.

Attaching screenshots of both devices. Used the Map Viewer Demo to demonstrate.