I do too, when I'm speaking aloud. In my experience, though, when writing, the actual degree is listed(PhD, MD, EdD, JD, DDS, etc.), rather than the more generic "doctor".

edit: Just checked; the AP and Reuters style guides both seem to recommond only using Dr for Medical Doctors. That's probably where my memory comes from.

http://www.sandiego.edu/web/pdf/brief_ap_style.pdf http://handbook.reuters.com/index.php/D#doctor