BlockUI Ignores the Width and Height CSS when theme = true

BlockUI Ignores the Width and Height CSS when theme = true

I have the following code:

$.blockUI({ 
         css: { 
                width: blockwindow_width + "px",
                height: blockwindow_height + "px",
                top: ($(window).height() - blockwindow_height) /2 + 'px', 
left: ($(window).width() - blockwindow_width) /2 + 'px', 
         },
         message: $('#domMessage'),
         theme: false,
        });

which works as expected, with a big centered div popping up in the middle of the screen, but if I turn theme to 'true' it all of a sudden goes to 30% width and opens half way down the page.

I am using the redmond theme:

<link rel="stylesheet" href="http://ajax.googleapis.com/ajax/libs/jqueryui/1.8.2/themes/redmond/jquery-ui.css" type="text/css" />

and JQuery from Google:

<script type='text/javascript' src='http://ajax.googleapis.com/ajax/libs/jquery/1.4.2/jquery.min.js'></script>
<script type='text/javascript' src='http://ajax.googleapis.com/ajax/libs/jqueryui/1.8.2/jquery-ui.min.js'></script>

I've also attached two screen shots as an example. Thanks!