Date picker was working fine up to an hour ago while using v.1.5.2. I just tried 1.6 Beta now and everything seems to work fine except date picker option.
Just in case it could be a Jquery issue instead of a beta version issue I read the thread http://www.gravityhelp.com/forums/topic/gravity-forms-v15-beta-2-date-picker-not-showing-up several times and everything seems fine in my site to me. However, so far I have not been able so solve the issue by myself.
My test form can be found at http://ofertazo.net/ropa-gravity/
