I've used this php file http://www.barattalo.it/2010/02/24/ping-pingomatic-com-services-with-php/
and this is the debugging info :
HTTP/1.0 200 OK
Server: nginx
Date: Mon, 09 Apr 2012 17:36:24 GMT
Content-Type: text/xml;charset=utf-8
Content-Length: 345
X-Cache: MISS from proxy34.samanet.sy
X-Cache-Lookup: MISS from proxy34.samanet.sy:3128
Via: 1.0 proxy34.samanet.sy (squid/3.0.STABLE19)
Proxy-Connection: close
<?xml version="1.0"?>
<methodResponse>
<params>
<param>
<value>
<struct>
<member><name>flerror</name><value><boolean>0</boolean></value></member>
<member><name>message</name><value><string>Pings being forwarded to 10 services!</string></value></member>
</struct>
</value>
</param>
</params>
</methodResponse>
does the result mean everything worked? If not, what is the error?
You can find the signification of HTTP Status Code from here
And by the way your log says that everything is ok, i quote :
10.2.1 200 OK
The request has succeeded. The information returned with the response is dependent on the method used in the request, for example:
GET an entity corresponding to the requested resource is sent in the response;
HEAD the entity-header fields corresponding to the requested resource are sent in the response without any message-body;
POST an entity describing or containing the result of the action;
TRACE an entity containing the request message as received by the end server.