Thanks, Kwok - was not sure where to look for that. It seems to be the same as the basic settings.txt, but I dropped in that chunk anyway. I'll see if that does it. Does not seem to ever shuffle when Devnull is running for some reason. I'll post if I ever discover why...
Curiously, dropping in what looked to be identical code from the standard settings.txt file did the trick. No idea why, but now the music is shuffling properly. Thanks for the suggestion. Very odd. [shrug]