The first time you set the transformOriginPoint of an item, the setting is ignored.
In the example below - click the "Set rotation" button. The red square is rotated about the centre point, even though the transform origin is set to 10, 10. Click "Reset" then do it again. This time the correct origin is used.

iimport Qt 4.7

Rectangle {
width: 400
height: 400

Rectangle

{ id: fred x: 100 y: 100 width: 200 height: 200 color: "red" }

Rectangle {
y: 270
width: 100
height: 30
color: "grey"
Text

{ text: "Set rotation" }

MouseArea {
anchors.fill: parent
onClicked:

{ fred.transformOriginPoint = Qt.point (10, 10); fred.rotation = 45; }

}

}

Rectangle {
y: 310
width: 100
height: 30
color: "grey"
Text

{ text: "Reset" }

MouseArea {
anchors.fill: parent
onClicked:

{ fred.rotation = 0; }

}

}

}