Professor So-and-So?

i call my lecturers/tutors whatever they asked to be called, it can't be rude to call them by their first name if they ask to be. though sometimes if i'm unfamiliar with them i call them by Mr. xx or just try to catch their attention without mentioning their name/title. though i guess it also depends on the lecturer, one of my lecturers last year insisted we called him by his first name and would even go to the pub with us to go over our module problems. while a teacher of mine who had a long complicated greek name insisted you addressed her fully as Dr Papakosta...(forgotten the rest now) or she would just ignore you, you could only call her Dr P if she liked you, ie was taking A level chemistry.

Jam it back in, in the dark.