vitrual slot troubles

[GreenScape]

hello. i have an error(Segmentation fault) inside qt_metacall of my class:

int cl_StyledHeadersTableBase::qt_metacall(QMetaObject::Call _c, int _id, void **_a)
{
    _id = cl_TableViewBase::qt_metacall(_c, _id, _a);
    if (_id < 0)
        return _id;
    if (_c == QMetaObject::InvokeMetaMethod) {
        switch (_id) {
        case 0: styleChanged(); break;
        case 1: horizontalHeaderRequestContextMenu((*reinterpret_cast< const QPoint(*)>(_a[1]))); break; // <- HERE

int cl_StyledHeadersTableBase::qt_metacall(QMetaObject::Call _c, int _id, void **_a)
{
    _id = cl_TableViewBase::qt_metacall(_c, _id, _a);
    if (_id < 0)
        return _id;
    if (_c == QMetaObject::InvokeMetaMethod) {
        switch (_id) {
        case 0: styleChanged(); break;
        case 1: horizontalHeaderRequestContextMenu((*reinterpret_cast< const QPoint(*)>(_a[1]))); break; // <- HERE

To copy to clipboard, switch view to plain text mode 

horizontalHeaderRequestContextMenu(QPoint*) is a virtual protected slot:

protected slots:
    virtual void horizontalHeaderRequestContextMenu(const QPoint & pos);

protected slots:
    virtual void horizontalHeaderRequestContextMenu(const QPoint & pos);

To copy to clipboard, switch view to plain text mode 

but when i erase virtual keyword there is no such error.
i found that virtual slots are allowed (Qt doc).
so what am i do wrong?
thanks.