I believe this could very well be true. Let me tell you why. There were replacement trannys that were shipped as late as the November timeframe that did not resolve the problem. I believe there were a couple of people on this very board who experienced this, but my timing/memory could be a bit off. It appears to me that BMW may not have had their "arms around" the problem until November/December where they finally realized it was a defective clutch assembly. Therefore, replacement trannys had to be ordered with that latest fix. I would assume that there is a limited inventory and capacity for replacement trannys ... especially ones that are brand new in design. This is why a backlog makes sense to me. My dealer claims that I was one of the first to obtain a replacement tranny that truly corrects the problem. I'm still not so sure ... have an appt. at the end of Feb. to have the shop foreman test drive it. But if that is true, my tranny was ordered just before Christmas, arrived between Christmas and New Years, and was installed second week of January. That should give you an idea of timeframes when ... assuming what they are saying is true ... the first "fixed" trannys began to arrive.
I'll fill you all in when I take my car in on 2/24 as to whether it's really fixed or not. In the morning, when I shift into "D", the car moves forward at a very slow speed (doesn't even register on the speedometer), and I am able to get the rpms from 800rpm to about 1200 rpm with no further acceleration. Once I hit about 1300-1400 rpm, it does accelerate. So ... my question to my shop foreman is whether this is normal and whether it is slippage.