The rate rules are what matters and it says nothing about prepayment.
HOWEVER, you did not post what the cancellation policy is and it is always listed somewhere in the reservation. The cancellation policy may shed light on whether something is amiss with the rate rules. If there is no cancellation policy listed in the rate rules, then there may be something amiss. As an example below are the rates rules for an advanced purchase rate at RCC:
Additional Information
Rate Includes Breakfast for 2
Holding Your Reservation
* We will need a credit card prepayment to reserve your room.
* To insure that you receive this special advance purchase rate, we will charge your credit card a prepayment of 224.25 GBP (your full room charge plus tax) when you make your reservation.
Canceling Your Reservation
* Please note that changes to your reservation are not permitted.
* Please note that your prepayment for this special rate is non-refundable.
Modifying Your Reservation
* Changes to your reservation are not permitted.
* A reservation made 14 day(s) before your expected arrival.
I wouldn't be concerned as everything jives (haven't used that word since the 70s) with the rate rules, but if you are still concerned you can always call Marriott reservations and inquire. They will probably tell you the same thing I did, either that or they will contact the hotel and get back to you.
BTW - Vail Marriott reservations are misleading too. When viewing the the available resevervatiosn for the ski season you see the following:
Regular rate, prepay in full, non-refundable, see Rate Rules
And then when you read the rate rules you get:
******************SKI SEASON DEPOSIT POLICY*****************
21 November 2008 through December 18 2008
Reservations traveling November 15 through April 19 are subject
to an advance deposit. This deposit will be required 30
days prior to the scheduled arrival on all paid reservations.
19 December 2008 through April 19 2009
Reservations traveling December 20 through April 19 are subject
to an advance deposit. This deposit will be required 45 days
prior to the scheduled arrival on all paid reservations.
****************SKI SEASON CANCELLATION POLICY**************
21 November 2008 through December 18 2008
Cancellations are permitted up to 31 days prior to arrival fo
a full refund. Cancellations which occur between 0-30 days
prior to arrival are subject to a cancellation fee equal to all
nights purchased.
19 December 2008 through April 19 2009
Cancellations are permitted up to 46 days prior to arrival for
a full refund. Cancellations which occur between 0-45 days
prior to arrival are subject to a cancellation fee equal
to all nights purchased.
*******************SKI SEASON CHANGE POLICY*****************
21 November 2008 through April 19 2009
Changes to the dates of travel are not permitted once the
reservation is within the cancellation penalty period.
Other than the fact that they haven't updated their rate rules for 2009/2010 ski season, they are still the standard 45 day deposit and may be canceled 46 or more days prior to scheduled arrival. I booked a reservation 5 weeks ago for January 2010 and they have not charged my card yet and they won't until early December.