Todd Parker, jQueryMobile Project lead, confirmed by email today that my rounded corner issue (1751 under github) is now fixed and fully part of the new jQuery Mobile release. This new release has caused a new change and we have to decide as a team whether we like the new look of the collapsed collapsible. This now has a background colour. This was reported by MauriceG as issue 2467 . The JQM team is now looking at possibly removing the background colour and offering the user the choice to ‘opt-in’. Will update as this become available.