Hi, I have also some thing like that. In fact, there is no ghost "smoke" behind the clocks and not behind the apps. This appears only behind the "faces" (that I get when I slide up from the clock) and behind the notification (when I slide down from the clock). It's like those screens have a "transparent" background, and the apps have "non transparent" background. So behind the faces and the notifications, I can see some "greyish clouds", not always the same shape, but sometime it is quite difficult to read the information that the face displays, as this "smoky things" blurs the screen.
Someone may have same thing or any idea ? Thanks.
I bought the sport watch in France two weeks ago, but now I'm back in Thailand were the watch isn't sold yet. I will not be back to France before September.