symbol lookup error: /usr/lib/libQtOpenGL.so.4: undefined symbol +opencv

Hi
I've installed opencv2.2 from source and tried to compile an example but i get this example :
symbol lookup error: /usr/lib/libQtOpenGL.so.4: undefined symbol:_ZN14QWidgetPrivate15checkWindowRoleEv
this is the main.cpp file :

Code:

---

#include <QtGui/QApplication>
#include "widget.h"
#include <stdlib.h>
#include <stdio.h>
#include <math.h>
#include "cv.h"
#include <cvaux.h>
#include <highgui.h>
#include <cxcore.h>
 
 
int main(int argc, char *argv[])
{
    QApplication a(argc, argv);
    //Widget w;
    //w.show();
    IplImage* img = 0;
    int height,width,step,channels;
    uchar *data;
    int i,j,k;
 
    if(argc<2){
      printf("Usage: main <image-file-name>\n\7");
      exit(0);
    }
 
    // load an image
    img=cvLoadImage("/home/aladin/image1.png");
    if(!img){
      printf("Could not load image file: %s\n","/home/aladin/image1.png");
      exit(0);
    }
 
    // get the image data
    height    = img->height;
    width     = img->width;
    step      = img->widthStep;
    channels  = img->nChannels;
    data      = (uchar *)img->imageData;
    printf("Processing a %dx%d image with %d channels\n",height,width,channels);
 
    // create a window
    cvNamedWindow("mainWin", CV_WINDOW_AUTOSIZE);
    cvMoveWindow("mainWin", 100, 100);
 
    // invert the image
    for(i=0;i<height;i++) for(j=0;j<width;j++) for(k=0;k<channels;k++)
      data[i*step+j*channels+k]=255-data[i*step+j*channels+k];
 
    // show the image
    cvShowImage("mainWin", img );
 
    // wait for a key
    cvWaitKey(0);
 
    // release the image
    cvReleaseImage(&img );
 
    return a.exec();
}

---

and this is the .pro file :

Code:

---

#-------------------------------------------------
#
# Project created by QtCreator 2011-05-10T14:34:50
#
#-------------------------------------------------
 
QT       += core gui
 
TARGET = opencv2
TEMPLATE = app
target.path=/usr/local/bin
INSTALLS=target
INCLUDEPATH +=/usr/local/include/opencv/
LIBS +=-lopencv_core -lopencv_imgproc -lopencv_calib3d -lopencv_video -lopencv_features2d -lopencv_ml -lopencv_highgui -lopencv_objdetect -lopencv_contrib -lopencv_legacy
 
SOURCES += main.cpp\
        widget.cpp
 
HEADERS  += widget.h

---

please can someone help me to fix this ?

Thanks in advance.