Compliance in PowerPoint 2003 Presentations and 2007

[Ferla]

Hi,

I've done a presentation in PowerPoint 2003 and I used many pictures that I
take by PrintScreen. When I open this presentation in PowerPoint 2007 some
pictures doesn't appear, but they continuos there.

I suppose that this pictures are bitmaps type and I convert to gif or jpeg
and for my surprise the pictures appear again.

Is there some uncompatible between bitmaps pictures types in Office 2003 and
Office 2007?

Someone can explain this for me?

I appreciate any help or any light.