One well known problem experienced by Microsoft Office users in Mac and Windows environments is that some images inserted using the Mac cannot viewed in Office for Windows. Instead of seeing the image, you get an error message that says "QuickTime and a TIFF (LZW) decompressor are needed to see this picture." Typically this problem happens with images that have been inserted in the documents using the clipboard or drag and drop.
The quickest and easiest way to solve this problem in old documents is to use the red eye removal tool (or some other non-noticeable adjustment tool) in iPhoto or Photoshop on the images, as described in this blog entry. For new documents, the standard solution is to use Insert » Picture » From File in Office (as described here), but it is not as comfortable or fast as using the clipboard or drag and drop.
An easier way to avoid this problem uses Skitch as a translation tool. Instead of dragging the image from Safari or other program to Word or PowerPoint directly, you should drag it to Skitch first. Then, you have to drag it from Skitch to Word or PowerPoint, using Skitch's "drag me" handler. It's very important that you select .jpg or .png as file format in Skitch, just over the 'drag me' handler. Alternately, you can use the clipboard to do this operation.
For more information (only in Spanish, sorry), you can read this post on my blog.
Mac OS X Hints
http://hints.macworld.com/article.php?story=20081013092730881