I'm trying out OmniGraffle 5.1 and have hit a snag: On my Mac, I have copied a simple diagram from OmniGraffle into a PowerPoint 2004 slide. I have then sent the .ppt file to a colleague who is using PowerPoint 2007 on a Windows Vista machine. When he opens the file, however, he sees only a blank slide and a message, "QuickTime and a decompressor are needed to see this picture."

Is QuickTime needed wherever someone wants to view a presentation containing a diagram that has simply been copied and pasted directly from OmniGraffle? What's the most robust solution for getting OmniGraffle diagrams into PowerPoint (without losing resolution of the graphic)?