Manda,
When I booked a couple weeks ago, the woman taking my reservation for the Dolphin also told me that my dates (Dec. 27 - Jan. 2) did not qualify for the teacher rates. But I was able to tell her that I had been on their website the night before, and that all but my last night qualified (the night of Jan. 1). She checked into it and said "Yes, you are right"! She then told me to hold for a minute so she could try to find me a decent rate for my last night. She came back with a better price than the usual rack rates, and said she wouldn't charge me the extra $25 for our adult son on that last night. Very nice!
My advice to you is that if you really would like to stay at the Swan or Dolphin, you should be able to get the teacher rate for all but your last two nights. I think the reason for no teacher rate for the end of our stays is because they are in 2010. They probably don't have teacher rates listed for 2010 yet.
The woman also said the rates would probably be changing anyway. Not sure what that meant, but I'm hoping she said that knowing that by this time next year, the teacher rates would be out for 2010!?! Wishful thinking maybe, but makes sense.
Hope this helps!