Krystal,
I'm not sure where you read that you can't use Disney Dining credits? You definitely can. I looked through many of our posts on the Moms Panel and can't find any that state otherwise (but I might have missed it). Perhaps you read it elsewhere.
Anyway, the Fantasmic! Dinner Package is available at three qualifying restaurants: The Hollywood Brown Derby, Mama Melrose, or Hollywood & Vine. If you use the Disney Dining Plan, it uses one table service credit for either Mama Melrose or Hollywood & Vine, and two credits for the Brown Derby.
If you don't use the Disney Dining plan the costs for the meal is (as of early 2008, excluding taxes and gratuities):
Brown Derby: $46.99 per adult
Mama Melrose: $32.99 per adult
Hollywood & Vine: $ 24.99 per adult
Cost for children (ages 3-9) are $11.99 each at all three restaurants
If you want more details about the Fantasmic! Dinner Package, click
here to read a more detailed prior post on this topic.