i have opened a Support Case for this one. They told me i have to use a welcome page with a script to store the original url in a cookie.
the welcomepage with script looks like this, but it is still not working
<html>
<head><script>
{
function createCookie(name,value,days){
if(days) {
var date=new Date();
date.setTime(date.getTime()+(days*24*60*60*1000));
var expires="; expires="+date.toGMTString();
}
else var expires="";
document.cookie=name+"="+value+expires+"; path=/";
}
var q=window.location.search;
var errmsg=null;
if (q && q.length>1) {
q=q.substring(1).split(/[=&]/);
for(var i=0; i<q.length-1; i+=2){
if(q[i] == "errmsg"){
errmsg = unescape(q[i+1]);
break;
}
if(q[i]=="host"){
createCookie('url',unescape(q[i+1]),0)
}
}
}
if(errmsg&&errmsg.length>0){
errmsg="<div id='errorbox'>
"+errmsg+"
</div>
";
document.write(errmsg);
}
}
</script>
<script>
{
function readCookie(name){
var nameEQ = name + "=";
var ca=document.cookie.split(';');
for(var i=0;i<ca.length;i++) {
var c=ca[i];
while (c.charAt(0)==' ') c = c.substring(1,c.length);
if (c.indexOf(nameEQ) == 0) return c.substring(nameEQ.length,c.length);
}
return {};
}
var cookieval=readCookie('url');
if(cookieval.length>0) document.write("<meta http-equiv=\"refresh\" content=\"2;url=http://"+cookieval+"\""+">");
}
</script>
</head>
<body bgcolor=white text=000000>
<font face="Verdana,Arial,Helvetica,sans-serif" size=+1>
<b>User Authenticated</b>
<p>In 2 seconds you will be automatically redirected to your original webpage</p>
<p>Presscontrol-d to bookmark this page.</p>
<FORM ACTION="/auth/logout.html">
<INPUT type="submit"name="logout"value="Logout">
</FORM>
</font>
</body>
</html>