Philips Seismic Edge Sound Problem

[Smoke Eater]

Hope this is the correct area to ask this question, if not, I apologize and please re-direct me....I'm normally over on the video forum. I've installed a Philips Seismic Edge sound card in my htpc (5.1 channel PCI). Since installing it, I have been getting intermittent "drops" of the audio. The sound will just stop for a second or two and then start again. I finally located what was initiating the problem: anytime a "switch" is thrown in the house (light switch, refrig kicking on, etc...) it causes the htpc to stop the audio (video/screen remains fine). I've checked the house grounds at the suggestion of someone else, and they seem fine. I run a surge protector at all times, but this seems to be more of a voltage drop problem. Any suggestions? Thanks in advance, R