Quote Originally Posted by MarekR22 View Post
It looks like that QGraphicsItem::boundingRect of this arrow is incorrect or you do not call QGraphicsItem::prepareGeometryChange before value of boundingRect is changed.
Hmm... I didn't know that I had to call QGraphicsItem::prepareGeometryChange before changing the bounding rectangle. Quite stupid actually, because the doc for QGraphicsItem::boundingRect states that if you want to change the item's bounding rectangle, you must first call prepareGeometryChange(). Oops...

Once again, I'm amazed at how you guys can pinpoint the cause of my problems with the little information I provide. Thanks!