[Angostura]

I'm not seeing that behaviour at all direct from Google. I do get the registration overlay if I subsequently click another Quora article page from the original Quora article. The behaviour I'm seeing is reasonable, if slightly annoying.

[Smirnoff]

Here, I quickly recorded the above-mentioned situation and posted it on youtube: http://www.youtube.com/watch?v=xiOMwRwXLcg