Not able to fade in/out Dialog

Not able to fade in/out Dialog

I am not able to fade in/out Dialog in jQuery UI.

The code I'm using is:

  1.        someElement.dialog({
  2.             title: 'Example',
  3.             show: 'fade',  // I've tried using fadeIn as well.
  4.             hide: 'fade'
  5.         });
When I don't include Effects Core, this gives me a 'size' effect, where the dialog resizes from the top-left.

And when I do include Effects Core, the dialog is not displayed.

I've looked up in the forums and elsewhere, but haven't found a solution. I'm using jQuery UI 1.8.1.

Thanks!

I'm not including any other effect's code.