Bounce not working on first open of a dialog window

I am using the following code to open a dialog window with a bounce effect.

$( "#dialog" ).dialog({show: { effect: "bounce", duration: 800 }, buttons: [ { text: "Ok", click: function() { $( this ).dialog( "close" ); } } ] });

The first time I open the dialog window it doesn't bounce. It bounces for all subsequent opens.