jQuery Tools Overlay invokes vertical Scrollbar in IE

When i open a JQT Overlay with Internet Explorer 8 the first time, a vertical scrollbar appears in the main window. When i close the overlay and open it again, the scrollbar won't appear. How can i avoid the appearance of the vert开发者_如何学Goical scrollbar when i open the overlay the first time?

The only answer i have found so far to fix this problem in IE8 is to open up your JqueryUI css file, and find the .ui-widget-overlay selector and add the following rule :

position: fixed; 

so effectively:

.ui-widget-overlay  { position: fixed; }