I have the same thing with 2 lifecams vx3000 and vx6000 :(((. the vx3000 started buzzing after about 4-5 months while the 6000 was bad almost right from box. I'm gonna play with the interference idea tomorrow.
Microsoft Lifecam Vx-3000 Software Download
OK, I opened the 6000, and started to play with the mic. Couldnt see much so I opened the lifecam software, went into the page with the audio meter (audio settings or smth like that) and observed how it reacts when i played with the mic... after few "pokes" i noticed the bar went down (ie the buzz was gone).. so i gently put the mic back into its place and closed it... so far its working. We'll see the other one soon.
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