ExcelBanter - IE 7 Excel Sheets disapperaing

I have a simple html page with a IFRAME.

If you create two excel workbooks (sample1 and sample2 ) with two
sheets each and run the example.

You will notice that after you load the second document. Sheets in
work book start disappearing.

Can some one, please let me know any solution / workaround.

Configuration (IE 7.0 AND Excel 2003 SP2)

<Html
<head
<script language="javascript" type="text/javascript"
function doSome(){
var e = document.getElementById("sme");
e.src = "sample2.XLS"
}

</script
</head

<Body

<input type="button" id ="myButton" text ="MyButton" value =
"myButton" onclick="javascript:doSome()"/
<br

<iframe src ="sample1.XLS" height="600" width="1300" id ="sme"/

</Body

</Html