User Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:36.0) Gecko/20100101 Firefox/36.0 Build ID: 20141126030207 Steps to reproduce: I am on windows 7 x64, 32bit Firefox Nightly (up to date as of this entry) using e10s and I have tried this with a clean profile. Navigate to a page with a select box that has a scroll bar in it (https://bugzilla.mozilla.org/enter_bug.cgi?product=Firefox&format=__default__) and open the select box (the dropdown next to OS on the above page) Actual results: A different select box is shown than I would expect. This box seems IMHO to be worse UX as you cannot tell where in the list you are, or how long it is. Also it is harder to move quickly through the list. Expected results: The standard windows select box should have been shown, while the one shown does look native it is not the one I would expect (I don't know the proper names for the different select boxes). I have attached a screen shot with e10s and without.

Moving from Core::Untriaged to Core::General https://bugzilla.mozilla.org/show_bug.cgi?id=1407598