As mentioned in my last posting on OpenSuse 10.2 in Virtual PC 2007, I could not get sound to work.  After just installing Mandriva 2007, I encountered the exact same problem.  After a little research, I found the answer here: http://www.linuxquestions.org/questions/showthread.php?t=149181

  1. Open up a command line terminal session (usually you would just right-click on the desktop and choose "Terminal")
  2. Type su and press Enter.
  3. Enter the root password and press Enter.
  4. Type cd /sbin and press Enter
  5. Type ./sndconfig and press Enter.
  6. Introduction: Press Enter.
  7. Probe Results: Press Enter.
  8. Card Type: Select Sound Blaster 16 and press Enter.
  9. Card Settings:
    1. I/O Port: Select 0x220 and press Tab.
    2. IRQ: Select 5 and press Tab.
    3. DMA 1: Select 1 and press Tab.
    4. DMA 2: Select 5 and press Tab.
    5. MPU I/O: Select 0x330 and press Tab.
    6. Press Enter
  10. Sound Card Test: Press Enter
    NOTE Sound volume may be very low, adjust speakers accordingly.
  11. Test Result: Press Enter if sound was heard, if not, Tab to select No and press Enter.
    NOTE If no sound was heard, the most likely cause is lack of volume
  12. If File Exists: press Enter to overwrite the existing config file.
  13. Type exit and press Enter to exit the root console.
  14. Type exit and press Enter to exit the standard console.

As I have already deleted my OpenSuse VPC image, I wasn't able to test and see if it worked, but I can confirm that sound works in Mandriva 2007 (within Virtual PC 2007) with the above steps.  I hope this helps someone out!