Question: **UPDATE**  

I have reverted back to Jquery 1.3.2 and everything is working, not sure what the problem is/was as I have not changed anything else apart of the jquery and ui library versions.

**UPDATE END**

I having an issue with the [JQuery UI datepicker](http://jqueryui.com/demos/datepicker/). The datepicker is being attached to a class and that part is working but the datepicker is not being displayed.

Here is the datepicker code I am using and the inline style that is being generated when I click in the input box that has the class ".datepicker". 

```
$('.datepicker').datepicker({dateFormat:'dd/mm/yy'});

display:none;
left:418px;
position:absolute;
top:296px;
z-index:1;

```

If I change the display:none to display:block the datepicker works fine except it dosen't close when I select a date.

Jquery libraries in use:

* jQuery JavaScript Library v1.4.2
* jQuery UI 1.8 jQuery UI Widget 1.8
* jQuery UI Mouse 1.8 jQuery UI
* Position 1.8 jQuery UI Draggable 1.8
* jQuery UI Droppable 1.8 jQuery UI
* Datepicker 1.8

Answer: 
Had the same problem that the datepicker-DIV has been created but didnt get filled and show up on click. 
My fault was to give the input the class "hasDatepicker" staticly. jQuery-ui hat to set this class by its own. then it works for me.
Had the same problem while working with bootstrap modal. I had accidentally set the z-index for `.ui-datepicker` using `!important` which overrides the date picker z-index css attribute on the element. Removing `!important` worked.