User Agent: Mozilla/5.0 (Windows NT 6.3; WOW64; rv:31.0) Gecko/20100101 Firefox/31.0 (Beta/Release) Build ID: 20140510004002 Steps to reproduce: Autoscrolling (middle mouse button) doesn't work inside iframes since Fx 31. Except when iframe src from same domain.

Mozilla/5.0 (Windows NT 6.3; WOW64; rv:32.0) Gecko/20100101 Firefox/32.0 WFM using latest Nightly, build ID: 20140511030203. Could you please try to see if this reproduces for you using: - a clean profile: https://support.mozilla.org/en-US/kb/profile-manager-create-and-remove-firefox-profiles#w_starting-the-profile-manager - safe mode: https://support.mozilla.org/en-US/kb/troubleshoot-firefox-issues-using-safe-mode

@Cornel Ionce [QA] Latest nightly 32.0a1 (2014-05-12) - nope, still doesn't work neither with clean profile nor safe mode (or both). Again - except when src from same domain.

kulmegil, can you link to a page where this happens or attach a test case? Thanks!

@Liz Henry :lizzard wykop.pl is polish reddit.com clone. It extensively uses iframes to display content from external sites (leaves it's votebar on top of external site content) example links: http://wykop.pl/ramka/1975714/oddaj-krew-dostaniesz-prezent-od-jednostki-wojskowej-komandosow/ http://wykop.pl/ramka/1986192/absurdalnie-wysokie-stawki-za-przejazd-autostradami-w-polsce/ http://wykop.pl/ramka/1983920/sejm-zdecydowal-posiadacze-prawa-jazdy-kat-b-beda-mogli-jezdzic-motocyklami/ You can chose any link on wykop.pl as long as it matches pattern "wykop.pl/ramka/id/..." but check if external site doesn't escape from it's frame (uses antyframes script)