So other than the tagged images does InCopy CS4 and InDesign CS3 work well enough together? We're testing a Windows copy of InCopy CS4 with a Mac copy of InDesign CS3 and are having some problems. The InCopy user can make edits to the story and saves, but the InDesign user is not getting a notification that file needs updating or is unable to see any changes opening the saved InCopy file. I've seen a thread suggesting that the two aren't completely compatible. http://forums.adobe.com/message/1277702#1277702 But it sounds as though you're having at least some success with the two.