What's your clients' understanding of your marketing procedures? I used to work for a large company that forbade any contractors/consultants to use our name in marketing. Our feeling was the project may have been done years ago, with different project personnel, and we did not want to be in the position of endorsing a firm where circumstances had changed.
Now, at my current job, our site describes projects, but leaves off client names. We also try to update the projects, not leave them up forever.