Marvin's guess is a fairly likely hypothesis.
But as I said on the other thread, there is a really fine line between PR and tech support. Many people aren't going to call in, but will just give up in frustration. Releasing even some basic information publicly can do an awful lot of good, vs. the usual (silent) tech support process. For example, "X people have called in, and we've been actively debugging with Y% of them for Z weeks and haven't found anything yet."
There are some groups in Microsoft that take an active interest in forums and newsgroups, to "take the temperature" of user complaints and wishes. (e.g. look at microsoft.public.windows.vista.general)
Streets and Trips doesn't seem to be one of these. That's a real oversight, in my opinion, especially for a consumer product.