Export macro - unexpected font changes

[steve]

Hi all:

I am using the following macro to break up a presentation in PPT 97
into individual slides (thanks to the MVPs who helped me with this a
while back...)

Sub BreakupPres()
Dim opres As Presentation
Dim oSld As Slide
Dim sSlideOutputFolder As String

sSlideOutputFolder = ActiveFolder

Set opres = ActivePresentation
For Each oSld In opres.Slides
oSld.Export Format(oSld.SlideIndex, "000") & _
(sSlideOutputFolder) & opres.Name, "PPT"
Next oSld
Set opres = Nothing
End Sub

Most of the time, this works perfectly. But just sometimes, usually
when running this on a presentation someone else has created, some
text boxes have their font changed.

I tend to work in arial - but when this happens fonts change to Times
New Roman, and tend to change to some larger 'default' size.

This seems to happen to text boxes which have been added in addition
to anything on the Master. On the Master itself, arial is used
throughout.

Why might this be happening? And why does it happen on the text boxes
of some presentations as opposed to others?

Really grateful for your help. Thanks guys.

Steve, England