[jmcinvale]

Some do indeed have that feature.

On my XP computer I had, the motherboard had a couple jumpers that could be set to leave the front or rear USB ports on all the time.

I'll try the sound card with an external power supply to rule out power issues.

EDIT:

Tried a 9 Vdc power supply and the issue seems to be resolved.

I'm guessing that because this is a laptop maybe the USB ports aren't capable of full power and perhaps that was causing an issue with the sound card.

EDIT:

Same problem. Audio cuts out for a few seconds after playing a bit.

The level indicator in the Windows sound devices tab under playback still shows signal though.