There is no OneCare service pack. I suspect that you mean you installed Vista Service Pack 1 offered via Windows Update or you installed XP Service Pack 3 by seeking it out since it is not yet offered on WU.
I recommend contacting the PC manufacturer for updated drivers for your audio devices. You can also obtain support for problems with Vista SP1 per the information here:
http://technet.microsoft.com/en-us/windowsvista/cc295800.aspx
or here:
http://support.microsoft.com/ph/11732#tab0
-steve