Sound/Gaming Issue

I know there are a lot of posts like this, but I haven't found one exactly identical to my problem, and no fixes have worked.

Problem: Sound makes skipping/crackling noises while playing MMO/RPGs.
This does not occur with (For example)Starcraft 2, which is a RTS game, same with Civ 5. However, it does occur with games like Rift and even KOTOR, which was released around 2002; same exact issue. This leads me to think it isn't a compatibility issue. My FPS is pretty nice too. It runs about 30-60 on new games.

All drivers are up to date; it's been checked several times.

Info on the system: The computer was doing this right out of the box. I bought it cheap and augmented it with a Video card and a larger PSU(from 250w to 500w) so that I could play newer games. I initially thought it was an issue with Rift, but soon learned otherwise. (Since it only happens while gaming.)

Next I figured it was sound card related. I started with the onboard. I updated it with no change. I then used a USB card I had laying around. Same issue occurred. Then I bought a decent PCI card, same thing. So I'm going to assume this isn't for lack of a sound card or driver related. I'm no longer convinced it's even a sound related issue.

Here are some specs for your enjoyment:

Operating System
MS Windows 7 Home Premium 64-bit SP1

CPU
AMD Athlon II X2 255 (3.1 ghz)

RAM
4.00 GB Dual-Channel DDR3 @ 533MHz (6-6-6-19)

Motherboard
LENOVO Tilapia CRB (CPU 1)

BIOS
Brand LENOVO
Version D2KT31AUS
Date 01/11/2011


Graphics
AL2216W (1680x1050@59Hz)
NVIDIA GeForce GTX 460

Audio
SB X-Fi Xtreme Audio (Creative) PCI Slot

Here is a DxDiag as well. Any helpful input would be greatly appreciated.

Edit: Observation, this problem does not occur constantly. It only occurs during loading screens and when I'm running, i.e. movement in the game. Everything is peachy when I'm standing still.

Are all the techs on vacation?