positioning problems in IE6/7

I have the following image style in my stylesheet. The positioning works great across browsers except for IE6/7:

#lvl_topnav img{bottom: 3px; float: right; padding-right: 5px; position: relative;}

Here is the containing div:

#lvl_topnav{position:relative; font-family:Verdana, Arial, Helvetica, sans-serif; font-size:9px; color:#FFFFFF; margin:0px; padding:7px 0px 7px 20px; text-transform:uppercase; background-color:#464646; width:748px; wid\th:728px;  z-index:2;}

In IE6/7, the image is pushed down about 20 pixels or so from where it should be. Any ideas would be appreciated.