Source: Photoshop Support Knowledgebase
Issue: After you edit an image in Adobe Photoshop CS2 and update the image in Adobe Acrobat, the image is moved to the bottom left of the page.
Solution: Use the TouchUp Object tool to move the image back into position.
In order to get the image into the exact location, create guides to mark the location of the image on the PDF page before you choose Edit Image. After you edit the image in Photoshop CS2, use the TouchUp Object tool in Adobe Acrobat to move the image to the location you marked with the guides.
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