Rails 3.1 + jQuery + jQuery UI = data is null

Trying to get jQuery UI to work with my rails 3.1 setup, but i keep
getting errors that i cant see posted anywhere, this is driving my
insane so please have a look =>

[application.js]
// This is a manifest file that’ll be compiled into including all the
files listed below.
// Add new JavaScript/Coffee code in separate files in this directory
and they’ll automatically
// be included in the compiled file accessible from
http://example.com/assets/application.js
// It’s not advisable to add code directly here, but if you do, it’ll
appear at the bottom of the
// the compiled file.
//
//= require jquery
//= require jquery_ujs
//= require jquery-ui
//= require_tree .

[application.css]

@import “jquery-ui-1.8.14.custom.css”;

If i try auto-complete demo, the code =>

gets rended to =>

but nothing fires.

if i try the datepicker demo i get a =>
data is null in firebug console when page is loaded
and then a inst is undefined when clicking it …

Anyone got any information about this ?!

I can see jQuery UI 1.8.12 in the rended application.js so i guess //=
require jquery-ui is working ?!

If i remove “//= require_tree .” it works…

If i remove “//= require_tree .” it works…

Thank you Niklas : really hard to find …