Brain Dump: Digital noise with SONAR Producer Edition

I'm still having issues with digital noise (or static, depending on how you interpret the sound) and dropout on my SPDIF connection.

I know for a fact I've got serious electrical problems, and I'd love to be able to afford a power conditioner just to see if that solves the problem. My Yamaha synth (M08) seems to be stable - it appears the EMU 0404 USB is the problem child. I did recently update the hardware drivers for the EMU, but that has not changed its behavior.

The main symptom is digital noise (static, or crackling) that occurs randomly during SPDIF recording (done in realtime from the keyboard...). It seems the EMU unit is dropping digital sync for some reason - my suspicion is noise in the AC power. The killer is I can't hear this until I playback the recorded track.

Usually, I just cycle the power on the synth and the 0404, and I can continue recording without problems....until the next AC pop comes over the lines...

..but this is really annoying. And time consuming.