Powershell 2 event handling

Question

Hi Powershell experts!

I'm trying to script Powerpoint with Powershell 2.0.

This site says there's a "PresentationOpen" event. However, Get-Member does not show this event. Also, when I try to do this:

register-objectevent $application PresentationOpen notification_event

it says: "Cannot register for event. An event with name 'PresentationOpen' does not exist."

Why is this event not accessible from PowerShell? Am I doing it wrong, and there is another way?

What I'm really trying to do is to wait until the presentation is fully loaded before I save it in another format. Not waiting causes PPT to freeze sometimes.

I'm grateful for any help!