I have a main PP presentaton of 24 slides and another shorter
sub-presentation of 11 slides that I want to run as a loop from within the
main presentation.   Slide 3 of the main presentation is simply a Command
Button when clicked runs the following:

Private Sub cmdStartStars_Click()
   Presentations.Open FileName:="C:\Church\CE_Study\URC_StA\Stars_00.pps",
ReadOnly:=msoFalse
   With ActivePresentation.SlideShowSettings
       .ShowType = ppShowTypeKiosk
       .LoopUntilStopped = msoTrue
       .ShowWithNarration = msoTrue
       .ShowWithAnimation = msoTrue
       .RangeType = ppShowAll
       .AdvanceMode = ppSlideShowUseSlideTimings
       .PointerColor.SchemeColor = ppForeground
       .Run
   End With
   SlideShowWindows(Index:=1).View.Next
End Sub

When the sub-presentation is saved as a .pps extension and the main
presentation is a normal PP .ppt this works perfectly.   When the 3rd slide
of the main presentation is displayed, I click on the command button and the
sub-presentation then loops continuously until I press 'Escape' and this
stops the sub-presentation and re-displays slide 3 of the main presentation
and I can then continue with the main presentation.
BUT, if I save the main presentation as a .pps and run it, when I click the
command button I get the following error message

 Runtime error '-2147188160(80048240) Presentation (unknown member):
Invalid Request.   The Powerpoint Frame Window does not exist

When I cancel this message it then goes on to loop the sub-presentation
correctly BUT when I press 'Escape' it does not return to slide 3 of the main
presentation but terminates the whole thing.

Any help to solve these two problems would be greatly appreciated.