HTC Desire :: Hissing & Popping On Headphones

Just curious about others' experience with the headphone audio on their Desires.I use etymotic ER-6i earphones. In a quiet room I set the volume to "1" (i.e., one notch above nothing) and it's still a bit loud. That's how sensitive they are.While playing music there is a very noticeable hissing & popping (more like a thumping). This noise can be isolated by turning the volume to "0" while the music is playing.Others have complained of this, and different people have claimed their music is crystal clear. I wonder if there's a common defect to many but not all desires. or if only those of us with particularly sensitive earphones can hear such quiet interference.Maybe it's something else causing it, like the wifi? I will experiment later.