Q3Table event filter problem

[batileon]

I m porting qt3 codes to qt4.
Here I have a class TableGrid which inherits Q3Table (inherit QTable originally)

class TableGrid : public Q3Table { 
	public:
		MyTableGrid( int numRows, int numCols, QWidget* parent, const char* name);
		void paintCell(QPainter *p, int row, int col, const QRect& cr, bool selected, const QColorGroup& cg);
};

class TableGrid : public Q3Table { 
	public:
		MyTableGrid( int numRows, int numCols, QWidget* parent, const char* name);
		void paintCell(QPainter *p, int row, int col, const QRect& cr, bool selected, const QColorGroup& cg);
};

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and I used this TableGrid in another class MyTable:

class MyTable : public QWidget
{ 
    Q_OBJECT
 
public:
    ...
    ...
    TableGrid* tbl; // Table
    ...
    ...
    ...
}

class MyTable : public QWidget
{ 
    Q_OBJECT

public:
    ...
    ...
    TableGrid* tbl; // Table
    ...
    ...
    ...
}

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And I called

tbl->installEventFilter( this );

tbl->installEventFilter( this );

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to set the event filter.

The objective is to filter the mouse button pressed event signal.

bool MyTable::eventFilter ( QObject * obj, QEvent * e ){
    bool retval = false;
    if( QString(obj->name())==QString("tbl") ) 
    {
	if( e->type()==QEvent::Resize ) 
        {
	    configTable();
	    retval = true;
	} 
	else if( e->type()==QEvent::MouseButtonPress ) 
        { 
		tbl_mousePress();
		retval = true;
	}
    }
    return retval;
}

bool MyTable::eventFilter ( QObject * obj, QEvent * e ){
    bool retval = false;
    if( QString(obj->name())==QString("tbl") ) 
    {
	if( e->type()==QEvent::Resize ) 
        {
	    configTable();
	    retval = true;
	} 
	else if( e->type()==QEvent::MouseButtonPress ) 
        { 
		tbl_mousePress();
		retval = true;
	}
    }
    return retval;
}

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This work in the past (QT3)
however I found that in QT4, the MouseButtonPress QEvent can no longer received when I click on the TableGrid.

Can anyone tell me what's going wrong??
Thanks a lot