Slot "columnsMoved" is not firing?

[TorAn]

I have a QAbstractTableModel-derived model attached to a QTreeView and I need to be able to track user movement of columns in the view. Luckily QAbstractTableModel has a signal "columnsMoved".
So, I do usual stuff:

ui.lstPairs->setModel(&_model);
bool res1 = connect(&_model, SIGNAL(columnsMoved(const QModelIndex&, int, int, const QModelIndex&, int)),
		           this, SLOT(columnsMoved(const QModelIndex&, int, int, const QModelIndex&, int)));
if (!res1)
	return;

ui.lstPairs->setModel(&_model);
bool res1 = connect(&_model, SIGNAL(columnsMoved(const QModelIndex&, int, int, const QModelIndex&, int)),
		           this, SLOT(columnsMoved(const QModelIndex&, int, int, const QModelIndex&, int)));
if (!res1)
	return;

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..
and slot implementation:

private slots:
void columnsMoved(const QModelIndex & sourceParent, int sourceStart, int sourceEnd, const QModelIndex & destinationParent, int destinationColumn);

..

void viewPairs::columnsMoved(const QModelIndex & sourceParent, int sourceStart, int sourceEnd, const QModelIndex & destinationParent, int destinationColumn)
{
	int i =5; // test
}

void viewPairs::columnsMoved(const QModelIndex & sourceParent, int sourceStart, int sourceEnd, const QModelIndex & destinationParent, int destinationColumn)
{
	int i =5; // test
}

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When I run it in debug the res1 variable is TRUE, so everything looks normal. Then I start moving the view columns using mouse and my slot is never called. (I place a breakpoint in int i = 5; line)

Question: what can be the problem that causes columnsMoved slot to never be called?
Thanks.