Images in Excel: SpreadsheetAddImage problem

Hi All

I am trying to add an image in an excel spreadsheet using SpreadsheetAddImage, but there seems to be a problem with this function. Using it seems to clear the entire spreadsheet of all existing images, even ones that have just been added, thus resulting in only one image displaying in the final excel document. Is this a bug? Is there a workaround for this problem?

My stripped-down code:

</cfscript>

     var sheet = SpreadSheetRead(xxxxxxx.xls');

</cfscript>

<cfloop from="1" to="#athletesLen#" index="i">

               <cfloop from="1" to="#chartsLen#" index="chartsIndex">

                        <cfchart

                            format="png"

                            name="idChart">

                            <cfchartseries type="bar">

                                <!--- chart code here --->

                            </cfchartseries>

                        </cfchart>

                        <cfscript>

                            var anchor = rowNr & ",1," & rowNr+10 & ",5";

                            SpreadsheetAddImage(sheet, idChart, "png", anchor);

                            rowNr += 11;

                        </cfscript>

                    </cfloop>

</cfloop>