So this is a very annoying bug. I saw it in the past, but couldn't reliably reproduce it. Then it seemed to be gone but in fact it simply didn't happen to be triggered by what I was doing. I can mostly reproduce it with latest TOT, given the unreliable nature of the bug I'm not sure of the exact context. Opening a search http://duckduckgo.com/?q=cat and trying to select and Ctrl+C copy the red informative text at the top seems to trigger it after a few times.