When your code queries PictureProperties of a shape, PowerPoint XP crashes (just disappears or offers to send an error report to MS, but gives no error messages).
The same code works fine in other versions of PowerPoint.
Solution
Be certain that the shape is, in fact, a raster picture before you reference any of its picture properties (transparency, etc.)
Among other things, check to see that it's an embedded picture, and try ungrouping it. If it will ungroup to a shaperange, it's not a raster picture.
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