InsertHtml problems with Safari

Hi,
I wanted to use the FCKEdtor 2.5 with safari
I'm trying to pass values to fckeditor using FCKeditor_OnComplete (see below)
This work with Firefox, but not with Safari
The editor is in an iframe (ajax web based)
Does anyone have any idea or a workaround to send the html source to the editor ?
Many Thanks

stdu

function FCKeditor_OnComplete( editorInstance )
{
var oEditor = FCKeditorAPI.GetInstance('FCKeditor1');
oEditor.InsertHtml( existingValue );
}