I am having problem with subscribing for notifications of call state changes. After sending request to Quadro2x:
<?xml version="1.0"?>
<methodCall>
<methodName>>Services.CallProcessingService.subscr ibe</methodName>
<params>
<param>
<value>
<string>TYCO_13</string>
</value>
</param>
<param>
<value>
<int>3</int>
</value>
</param>
<param>
<value>
<struct>
<member>
<name>extension</name>
<value>
<string>13</string>
</value>
</member>
</struct>
</value>
</param>
</params>
</methodCall>

... I am getting response (undocumented) like this:
<?xml version="1.0"?>
<?xml version="1.0"?>
<methodResponse>
<fault>
<value><struct>
<member>
<name>faultCode</name>
<value><int>1</int></value>
</member>
<member>
<name>faultString</name>
<value><string>Unknown XML RPC method</string></value>
</member>
</struct></value>
</fault>
</methodResponse>

My Firmware Version: 5.2.48/Release.

Any suggestions?
Thanks,
Janusz