aaike - oh I feel your pain. Every day I have something like this happen. I count myself an expert in Office, but that comes from years of frustration. Seemless integration and Office are complete oxymorons, but those who built its usability and feature sets are just plain morons. In addition, so many people have trouble pasting in images into ppt that look good (there are about 8 options under paste special, so who can blame them). Don't even get me started on Word tables or Visio! Any way, if your co-worker starts to rant on you for your "incompatible Mac" he/she is way off base and the same would happen if you were on a PC.
symphonix - I don't have my PC up here, but I'm betting aaike's coworker used an option under the Insert menu and had his/her link to file and/or save with file options checked the wrong way to create a "self contained" Word document. He/she should be able to resetablish these links, but in the future, it is just safer to paste special anything (pics, tables, spreadsheets...) into an Office doc rather than use the insert options.