Problem License key update

[ChristianL]

Hello,

since two weeks i can not update the license key.

Key-Update-Status
Server response: Key Authorization Problem

Now i can´t use plesk. I use it on a 1und1.de root server. Plesk 8.6 on a Debian Etch. I checked http://kb.odin.com/en/3969, the telnet to ka.swsoft.com on port 5224, and searched for corrupted key_history entries. I have a connection to ka.swsoft.com and no corrupted key_history entries.

I checked also:
curl -k https://ka.parallels.com:5224 --sslv2
curl: (35) error:1406D0CB:SSL routines:GET_SERVER_HELLO

curl -k https://ka.parallels.com:5224 --sslv3
<html><head><title>Apache Tomcat/6.0.18 - Error report</title><style><!--H1 {font-family:Tahoma,Arial,sans-serif;color:white;background-color:#525D76;font-size:22px;} H2 {font-family:Tahoma,Arial,sans-serif;color:white;background-color:#525D76;font-size:16px;} H3 {font-family:Tahoma,Arial,sans-serif;color:white;background-color:#525D76;font-size:14px;} BODY {font-family:Tahoma,Arial,sans-serif;color:black;background-color:white;} B {font-family:Tahoma,Arial,sans-serif;color:white;background-color:#525D76;} P {font-family:Tahoma,Arial,sans-serif;background:white;color:black;font-size:12px;}A {color : black;}A.name {color : black;}HR {color : #525D76;}--></style> </head><body><h1>HTTP Status 403 - Only PKP XML-RPC requests to /xmlrpc are allowed on the port 5224</h1><HR size="1" noshade="noshade"><p><b>type</b> Status report</p><p><b>message</b> <u>Only PKP XML-RPC requests to /xmlrpc are allowed on the port 5224</u></p><p><b>description</b> <u>Access to the specified resource (Only PKP XML-RPC requests to /xmlrpc are allowed on the port 5224) has been forbidden.</u></p><HR size="1" noshade="noshade"><h3>Apache Tomcat/6.0.18</h3></body></html>


What else can I check? How can i fix it?
Thanks for your help

Christian