Thanks for the responses! Investigation revealed that the power steering assembly is canted rearward slightly, enough to deflect or bind the drive belt slightly from the A/C pully. How do I get it to line up? I have tightened the PS assembly and now it really sings but stops after reving the engine! The problem is most pronounced when down shifting and turning a corner or when first pulling out after getting in the car, i.e., it doesn't squeal all the time. The upper bushings do appeared cracked, but not excessively. I am planning an A/C overhaul to convert the system to R-134a next month and may replace the bushings in one shot.

Chris, your observation is correct. The brakes moan just before coming to a stop and usually cease after several cycles of braking. However, John may also be correct that the shims were not re-installed after the rotors were turned. The local guy claimed to have worked for a Volvo dealership previously, but who knows.