Interesting. When I try that command I get this result:
HTTP/1.1 200 OK
Date: Wed, 14 Nov 2012 16:59:18 GMT
Server: Apache
Connection: close
Content-Length: 164
Vary: Accept-Encoding
Content-Type: text/xml
<?xml version="1.0"?>
<methodResponse>
<params>
<param>
<value>
<string>Hello!</string>
</value>
</param>
</params>
</methodResponse>