This is a Word bug that is easy to work around.

If you first paste some text, then immediately paste a Prism graph, it can appear as a frame only (no graph or image) and be partly off screen. The issues with cropping mentioned below regarding PowerPoint 2011 do not seem to affect Word 2011. However, Word does not let you ungroup it. Since the graph (or layout) is transferred in PDF format, the pasted image will be compact and crisp even when resized. Copying and pasting from Prism Mac (version 5 or later) to Word 2008 or 2011 just works.