We ran into this problem last fall and got so fed up with it, that we just use the DC discount (even though it is a lower discount, but the threshhold is lower as well). We stayed at BWV on points. We put down AMEX for incidental room charges. We tried to charge on our room key at DD. they wouldn't give us the AMEX discount. I told them that I put down an AMEX card for the room charges, so it should apply. The CM called BWV and spoke to them for about 5 minutes (no exaggeration on the time either). Finally, this is the answer they gave me (and it is in the tiny print on the White Glove treatment AMEX brochures that are all over Disney). The discount is only good if you paid for at least 2 nights room rates on the AMEX card. So we lost on that because we stayed on points. They went on to further explain that even though AMEX was the card used for incidental charges on the room, that did not count. It had to be the actual charge for the room that was on AMEX. At least the CM took the time to call my hotel to verify that AMEX was the card I put down for the incidentals, and then explain it to me. So at least they tried, but still didn't cut me a break. Unfortunately, all CM's do not seem to have the same knowledge of all of the programs and discounts, even though it is their job. We usually show all cards (DVC, DC, PAP, AMEX) and ask which gives the better discount, however there have been times where I happened to remember which was best and had to correct the CM. There were times where a CM flat out told us that there was no DVC discount, but once I got back to the room or home where I could look it up, sure enough a discount was listed for DVC members. Disney, DVD, DVC, etc. all need to communicate better to their CM's to explain the discounts and how they work, as well as to their PAYING customers.