It's a known issue, but, at the moment, I know of no workaround.
On 3/19/06 10:06 PM, in article
24EAB133-829F-4460-8F26-73BC112D11E4@microsoft.com, "Matt"
> Anyone know why the compatability report doesn't report the most useful thing
> which is if a user has copied and pasted pictures into there Mac 2004
[quoted text clipped - 6 lines]
> files back on the mac export the pictures save them as JPG's and re-insert
> them.

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Mickey Stevens (Microsoft MVP for Office:mac)
PowerPoint FAQ featuring PowerPoint:mac: <http://www.pptfaq.com/>
Entourage Help Page: <http://www.entourage.mvps.org/>
Andrew Chiang [MSFT] - 30 Mar 2006 05:05 GMT
Hello Mickey (and all those who are experiencing the issue below),
I have reproduced the issue and found that it is not specific to PowerPoint.
It also can occur in Word and Excel if you take the same user actions. It
just so happens that people are much more likely to insert images into
presentations than Word or Excel files.
Basically, the workaround (to be on the safe side) is to avoid dragging and
dropping or copying and pasting bitmaps/images from other applications. In
certain scenarios w/certain source apps, you may hit this issue.
It's best to use Insert Picture > From File... in each of the three
applications (Word, Excel and PowerPoint).
If you do find specific images that still exhibit this same issue when
inserted via Insert Picture > From File, we'd like to hear about it and
possibly get a copy of the image.
Thanks,
Andrew

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> It's a known issue, but, at the moment, I know of no workaround.
>
[quoted text clipped - 15 lines]
>> re-insert
>> them.