Popping during music play back

ok heres the deal…I just built my uncle a new computer here are the specs

Antec case and 550watt PS
2 16mb Cache 320gb WD HDD’s SATA 3.0
Creative Soundblaster X-Fi Xtreme Audio
EVGA GeForce 7300GS
Core2Duo 6300
Corsair XMS DDR2 800
2 Lite-on LH-20A1p’s DVD Burner’s
Asus P5B-E
Windows XP SP2

When using media player 11, and ripping CD’s while listening to music on the hard drive… on one of the drives…the music plays slow and pops…the rip is perfect and this happens only during playback…I thought it was the soundcard…so I moved PCI slots and then tried it on my computer…sound card is fine…I then thought it might be the drive itself…so I switched cables just to see and the problem moved from one drive to the other…so then I switched out cables completely and that didnt work…and finaly I switched the motherboard plugs that the drives were plugged into…problem still persist…

I am using the latest Bios…drivers and firmware…and have tried various configs, driver and firmware combinations…anyone have any input on what this may be…