This happened to me too. As another poster said, it is a little "sneaky" of Disney to change it up on a package you've already booked. But at the same time, we're modifying the reservation with a code so I guess that it's only fair that they can modify it too. As long as it doesn't end up costing more (which apparently can happen, so watch out for that).
At least I'm still saving some money on my package at POFQ. It's just not as much as I had hoped. So I guess I can't really complain.
I crunched the numbers and I am getting about 16% off the room with my my new Disney Visa package for December 17 - 26, 2007 (3 value nights, 6 holiday nights). But that 16% off is based on my original package where they were all value nights. So if I took into consideration that the base night rates could be variable, I am saving even more.
Other DISers are reporting savings of 30% - 40% with Disney Visa but that is for packages booked completely in the value season.
Oh well, at least we're still going to Disney!