Planner Item - Movement

Hi there

I have the Planner in Day Mode, with columns for Mon, Tue etc.
Within the planner I have a number of PlannerItems, which can be drag/dropped to the appropriate date/time etc.
When the PlannerItem is drag to the top of the planner (ie Item.ItemBegin = 0), the PlannerItem shrinks and produces a 'symbol' to show some of the planneritem is partially hidden.
Is it possible to stop this, so the planneritem can only go to ItemBegin = 0, ie it wont shrink.  Ive been using the OnItemMoving event with Allow := False.  However, when the event triggers Allow = true, it does not trigger the OnItemMoved event, which therefore causes problems.
Do you have any suggestions?  It there a property to disable PlannerItems from disappearing/shrinking of the planner?