Un slected dropdown menu items appearing randomly on different computers.

I have been working with the same set of interactive forms for a client for years and all has been well. Suddenly, a new set of office personnel and a few minor changes to company logo and the client reports that menu items that have not been selected by office personnel begin to randomly appear on the forms when emailed and opened by customers. This is causing a lot of confusion. I've never seen anything like it. The forms have always been bulletproof. Any ideas??

Hans