Why Symbian can't obtain user's position?

Question

I have the Symbian/MeeGo project which uses qt-mobility to obtain user's location. The problem is that the following code works fine on Meego (Nokia N9) and doesn't work at all on Symbian (tested on C6-01 and N8). It looks like the GPS adapter starts fine but it can't receive any position info. So we can see the "Satellite" icon near system clock but no coordinates are receiving. I've tested in a different conditions (inside/outside building, different weather conditions) and the result is always the same.

What can be the reason of this behaviour?

My code:

.pro

<...>
CONFIG += mobility
MOBILITY += location
symbian:TARGET.CAPABILITY += NetworkServices Location
<...>

.h

<...>
#include <QGeoPositionInfoSource>
#include <QGeoPositionInfo>
#include <QDebug>
<...>
QTM_USE_NAMESPACE

private:
   QGeoPositionInfoSource* mManager;

private slots:
   void newPos(QGeoPositionInfo);
<...>

.cpp

<...>
 mManager = QGeoPositionInfoSource::createDefaultSource(this);
 mManager->setUpdateInterval(1000);
 mManager->setPreferredPositioningMethods(QGeoPositionInfoSource::AllPositioningMethods);

 connect(mManager, SIGNAL(positionUpdated(QGeoPositionInfo)),
            this, SLOT(newPosition(QGeoPositionInfo)));
<...>
void QmlContext::newPosition(QGeoPositionInfo pos){
    qDebug() << pos;
}
<...>