I am cursed with C-Media sound drivers, courtesy of Microsoft. I cannot get rid of the d----d things. I uninstall C-Media drivers with the supplied utility. I then install a Creative PCI 128 card using the Microsoft Creative drivers and the sound is terrible. It's not hardware. I know that this is so because when I run a different copy of Windows XP (without having been so stupid as to let XP install C-Media drivers), the sound works well.
It would seem that the C-Media driver is interfering with the Creative one.
Owzat! On ya way, back to the pavilion!