Mac, you made some interesting observations, and I can understand your points. However, I would like to clarify some things: I said that "I suspect that here's the origin of a lot of users' headaches!" for several reasons:

First of all, just because I've seen a lot of users reporting ASIO problems with BIAB or RB in this forum.

Second, because I've used Asio4all with other programs without any problem; the only audio program in wich I've experienced problems with that driver is BIAB, wich made me think that the problem was on the particular way that BIAB manages ASIO drivers.

Third, because I still really can't see how some incompatibility between your ASIO drivers and your MIDI Output (wich is by no means PG Music fault) can cause a a total lack of audio output from BIAB. Just before posting that message, I tested the problem in Reaper to see how things worked there: if you use Asio4all there and activate the Microsoft GS Wavetable as MIDI Output, the program will inform you that "The following MIDI Outputs could not be opened: Microsoft GS Wavetable Synth", but after that everything will just work without problems (of course, if you selected the Microsoft synth as a MIDI output for any track, it won't work). The logic here is: since that specific MIDI Output don't work, it won't be availiable. The logic on BIAB, as I see it (please, correct me if I'm wrong) is: since that MIDI output don't work, nothing will work (even if you're not using the problematic MIDI output).

Fourth, because I have some experience in the way people uses to think when trying to solve computer problems (I've worked troubleshooting computers for several years) and, in my opinion, it would be really difficult for the average user (or even for the advanced user) to solve this problem by himself: I think there are just not enough information on the error message and / or some pieces missing in the puzzle.