Weird Sound Problem with wav Files



I have a SB Audigy sound card in my XP-based system. When playing wave files (system start-up, shut-down and other times) I sometimes hear distortion in the audio: “fritzing” (a static-like sound) or loud bumps in the audio. This only happens with wave files. TV, DVDs and CDs play fine.

Another piece of evidence, I hooked in a usb ATI remote transceiver and was waving around the wire antenna. Each time the wire touched metal, I would get that same loud bump and “fritzing” sound. It seems like a grounding problem. This is a home-built system. Any (rational) suggestions are welcome. Thanks.