The reason for this crackling might also be that the SB Live! series of sound cards is known to not be fully PCI 2.1 compliant. This causes the cards to be highly susceptible (just hope this is the right word ) to interferences when sharing an IRQ with other cards.
Windows XP, like Windows 2000 and unlike Windows 9x/Me makes excessive use of IRQ sharing. I only got rid of this problem by disabling ACPI on my Win2k machine and manually assigning a dedicated IRQ for my SBLive! in my PC's BIOS setup.
HTH,
Reaper out
