To do what you are being asked to do would be dishonest and unprofessional.
It's only dishonest if you don't disclose what you know. Otherwise, there's nothing wrong with it. I would disclose such as:
"My value is based on interior being in good condition that is free from any major damage. I completed an interior bpo on xx/xx/2010 and interior was in fair/poor condition. I was asked to complete this bpo based on interior bpo being in good condition without any damage."
It's the perfect solution and there is nothing unethical or dishonest about it. I've done it on several properties and never had a problem. Of course, I always keep a copy of the report. Plus, I don't burn any bridges over something that is pretty minor.