I didn’t think about the sound card, so I guess that’s a possibility. My Sound Blaster Zx is in a PCI-X1 slot (the short type). For me, the issue seems specific to iTunes. I did not get audio drop outs playing games, watching videos, watching Netflix etc.. I play COD Ghosts online a lot and it has some pretty complex audio. Also, the Zx processes all audio onboard and does not take any CPU cycles. That was one of its big selling points when I bought it.