It was a challenge.
If somebody meets such kind of situation I just want you to know that
This is a problem with iframe loading.
So simple reloading of iframe by means of javascript fix the problem.
function ReloadCuteEditorIframe() {
if (navigator.appName != "Microsoft Internet Explorer") {
var fr = document.getElementById('<%=CE_HTMLEditor.ClientID %>' + '_Frame'); // CuteEditor ID + addition frame tag
if (typeof fr.src != "undefined" && fr.src != null)
{ fr.src = fr.src; }
else window.setTimeout("ReloadCuteEditorIframe()", 1000);
}
}
and then you just put this server code where you need to show CuteEditor
ScriptManager.RegisterClientScriptBlock(this, this.GetType(), "RefreshIframe", "ReloadCuteEditorIframe();", true);