sound was working fine until latest KDE 4.3 updates arrived

System:

* Linux dev3 2.6.28-14-generic #47-Ubuntu SMP Sat Jul 25 01:19:55 UTC 2009 x86_64 GNU/Linux

* KUbuntu 9.04

* Latest updates from PPA repo installed.

* Everything was working great (removed the Network Manager applet to avoid crashing when booting/shutting down KVM VM's.) Best O/S ever!

Problem:

* downloaded large set of updates from the PPA repo.

* discovered later that sound had stopped working.

* after some tinkering: removed pulse audio entirely.

* In System Settings -> Multimedia:
  (a) click on Intel Sound device (onboard sound chip,) and
  (b) click the Test button at the bottom of the list to try to play the test sound.
  (b) see message above task tray: ... device not working, falling back to ...

* installed SysInfo from SUSE
   (-) observed that the hardware is properly detected and identified.

* In kmix:
  - Unmute MIC input
  - increase MIC gain very high
  - can hear hissing in headphones as expected.
  - raising / lowering volume sliders increases / lowers level of hiss as expected.

(In other words: The hardware appears to be working.)

* disabled motherboard-based intel sound chip.

* installed Sound Blaster Audigy card
   - same results as having on-board intel sound chip.

* plugged-in a USB sound adaptor
   - same results again.

* Installed GStreamer as second back-end for KDE - same results again.

* Searched forums & Google & Bing:
   - various sound issues with various time stamps appearing
   - no solutions to this particular problem have appeared.

Any help debugging would be much appreciated.
Thanks!