I have had problems getting confirmation letters consistantly for the last 2 years.
It was especially bad last September when we used the developer points from an AKV add-on. These were not the more restricted ones that they are giving out now, but at the time the reservation had to go through a "special" Member Services person. I've heard mixed reports about whether they are still doing it this way, but this definitely effected confirmation letters for developer point reservations. It took 3 requests and over 4 months to finally get one for that reservation. Since developer point reservations do not show up on the member website (you do not have to explain it to me, I know why), the confirmation letter is all you really have to know the reservation exists. Really puts a kink in using those "free" points!
However, I have had problems getting them for regular reservations, too. I find that it usually takes at least 3 weeks to get to me here on the left coast. I know I'm not close, but I can send letters across the country in 2-3 days so it just does not need to take this long.
Blahnde