I've complained many times of how many of my stays are not posted nor rewards given, and having to go to extraordinary lengths -- like going to the college to fax the receipt -- and even then waiting. This did happen again at the JW NOLA, but at least the past two times it's happened, I've been able to resolve things without having to fax results. Maybe it's because this stay was in the U.S., but I think all Marriott Elite Members should never have to prove they stayed at a property to get points and nights. Abroad it's been a mixed bag. Many post the day after I leave (not the least of which are my favorites (duh), the Ghent Marriott, Athens Ledra, and Rome Grand Flora).
I hope this is a sign that things really have changed. It still was a hassle getting my points at the JWNOLA, and two phone calls, but at least I didn't have to drive in a significant snowstorm to fax my bill. And if proof is every necessary, I would suggest that Marriott have a dedicated email site that can accept .pdf because I can do that from home.
Have you tried the online Fax applications? There are ones, like FaxZero (also several others) that allow you to do limited Faxes for free. I think FaxZero allows you to send a Fax of up to 3 pages, 2 times per day. Always nice to be able to do it without leaving the house.