I can say that I haven't noticed it. My wife is on the phone a lot so I'm sure I would have heard about it by now. The only complaint I have heard from her so far is the goofy call waiting tones, no MWI on my Panasonic phones, and my adapter hard locks up on occasion. VOIPo support enabled some additional logging on mine so they can see what was going on if it locks up hard again.

Scott