QGraphicsView mouse events

[high_flyer]

in order to debug this I sub classed QGrapicsScene.
The mouse event (in this case click event) gets delivered to the scene.
In the mouse event handler in the scene however, if I ask mouseGrabberItem() - I get -> 0, which means no item is grabbing the mouse - which means no item is getting mouse events.
Any idea idea what could be causing this?
I can't recall nor do I see this in the docs that I need to explicitly enable mouse grabbing on items since its a default behaviour (beyond setting the selectable flag).
(I am using Qt4.3 in this case, and grabMouse() is not yet available. But this should not be needed any how...)

EDIT:
all the items return true on acceptedMouseButtons ().testFlag( Qt::LeftButton)


help?