Thank heavens! I was about to post, asking how to get rid of them, as I thought it was part of the connection problem I've been having (now hopefully cured).
Like others, I'm seeing ads between posts, in some posts, and in the title header. I've also encountered a UK survey 'flash screen', which can not be cancelled by clicking the 'x' button, only by disconnecting from the 'net totally!
Glad to know it's not just me, and good to know Admin are on to it.