PowerPoint 2003 - Trapping "Save As"

[CaseOtherwise]

This thread is closely related to thread707-1080192, but my problem goes a little step further.

I'm also using the Powerpoint application event "PresentationBeforeSave" to start my own code when a user saves a presentation. Whenever the event "PresentationBeforeSave" is fired, I need to know if this is done because the user requested a "Save" or a "SaveAs", because I only want to call my own code to run with "Save" and not with "SaveAs".

The Word and Excel versions of this event both have a boolean parameter "SaveAsUI" which determines if the user chose for a SaveAs or a Save. The Powerpoint (Office 2003) version does not have that parameter.
Once a presentation has been saved already, the property .Path or .FullName both contain the path of that last save action, so this is no help either.

I also tried redefining the .OnAction-property of menu-button "Save As" in the Application.Commandbar-collection, but this doesn't seem a good option. (We abandoned this option because the code is supposed to run as part of an add-in. On PC's for which the add-in is removed later, the "Save As" will then be no longer able to perform properly.)

Does anyone have a suggestion?
Any help would be appreciated very much!

Thanks, KH