STR: - Go to http://www.scrollnroll.blogspot.com/ - Scroll down and middle click, the autoscroll icon will be displayed - Autoscroll up and down a few times - When your mouse accidentally hovers over a green double underlined word, a tooltip or popup appears - Every time the tooltip/popup disappears, also the autoscroll icon is dismissed Expected behavior: I think the icon should stay. This bug is caused by the fix of Bug 338639.

Firefox: 50.0a1, Build ID 20160705030222 User Agent Mozilla/5.0 (Windows NT 6.0; rv:50.0) Gecko/20100101 Firefox/50.0 I have tested this issue on the latest Firefox (47.0.1) release and the latest Nightly (50.0a1) build, but I could not reproduce it. For testing this I have used the provided URL. I have scroll the page with middle click, but when I hover over an underlined link, a pop up appears but the middle click does not disappears. Is this still reproducible on your end ? If yes, can you please retest this using latest Firefox release and latest Nightly build (https://nightly.mozilla.org/) and report back the results ?

Considering the fact that I cannot reproduce this and the fact that the reporter did not answered to my request until now, I will mark this as Resolved-Worksforme. If anyone can still reproduce it, feel free to reopen the issue and provide more information.