CF11 ColdFusion.Window.Create has no scrollbars

CF11 ColdFusion.Window.Create has no scrollbars. I have even tried overflow: scroll in the tag attributes and can't get it to work.

I'm on a Windows 2012 R2 Server.

<cfajaximport tags="cfwindow">

<TABLE>

<TR>

     <TD><img  border="1" src="/Utilities/Images/Icons/folders.ico" onclick="ColdFusion.Window.create('Window123','Sample Window','http://www.blueprintcss.org/tests/parts/sample.html',

        {x:100,y:100,height:500,width:500,modal:false,closable:true,

        draggable:true,resizable:true,center:true,initshow:true,refreshOnShow:false,

        minheight:200,minwidth:50,overflow: scroll})"/></TD>

    </TR>

</TABLE>