We have booked CL and then applied the AP discount when discounts finally applied to those dates.
There are some issues, we could not get an AP discount during our Nov 2010 trip and had to change to a woods view (at WL) to get any discount. On our Jan 2011 trip,
Dreams Unlimited was able to make the change as soon as the rates came out since there were AP rooms available. It really is hit or miss, January was a down time.
You can book the room, try to make the change on the day the AP rates come out (I would have a
travel agent do all this for you). Either be willing to change CL hotels or if you really want your hotel, maybe downgrade to a regular room.
AP discounts are good, but it seems like the general public discounts are coming out earlier than AP and filling some of the rooms.
Hope this helps.