I've come across this problem with MS Word 2003 a few times now.
When I paste a screen shot or image in MS Word, the graphic does not always show or intermittently shows. Instead it places a little red X in the top left of the image. I dont know if this has to do with grahical acceleration or Glide or some other system issue. When I print preview the document, its fine.
I have enough memory 3gc and am using Windows XP in a corporate environment. This happens even for a new document I start editing and paste images.