Are you absolutely sure its an electronic problem? The reason I ask is that you say it happens when you are walking around the room. It may just be room acoustics. If you walk to different places in a room while music is playing, the sound can change quite a bit depending on where you are. If you stand in one spot, for example, you could loose a lot of bass, but if you stand somewhere else, it could be stronger.
Other than that, you may want to check that cables of any kind, are not running under the carpet. Also swap out any cables that are connected to the Wadia to make sure they're not damaged.