Paul, have you, like me, tried to select and delete unused styles and have not been able to? (ID thinks they are being used, even though I can't find them no matter what I do.) Have you been able to solve the problem?
John, yes we have. We've seen that since CS1 when we started working with InDesign. No one to my knowledge has found a way to completely (easily) remove them. I believe that the problem is related to an invisible styled with an unused type face. I also seem to recall that the invisible had a style sheet applied to it but I might be wrong. As far as I know you can't search and replace type faces in those instances. You have to go through each style sheet one by one and manually look for the instances in the pages. It was so frustrating that we just began ignoring it. Maybe CS3 is different.