The whole purpose of the mandatory flight is training. The FI must be qualified to act as Commander; for a tailwheel aeroplane, this requires that the FI has completed tailwheel differences training and has 'TW' annotated in his personal log book upon completing that training. JAR 1.215 Appendix 1.
It sounds to me that your FI needs to look at the books.....
Meanwhile, you will need to fly with another FI who is qualified to fly tailwheel aeroplanes and then find an Examiner to revalidate your SSEA Class Rating onto the new system before the end of 30 Jun 2009.
bose-x....snap! You beat me to it!!