Use problem of libwww

My application follow the following structure :

/*Initialisation*/
HTProfile_newPreemptiveClient("testApp","1.0");

/*loop other the url I wan't to get */
    request=HTRequest_new();

    HTRequest_setOutputFormat(request,WWW_SOURCE);
    chunk=HTLoadToChunk(url,request);

    string=HTChunk_toCString(chunk);

	.........

    HTRequest_delete(request);

/*end loop*/

At a given url always the same, an error message is send by the application.
The error message is the following :

WARNING: Fatal error : System replies(NETREAD operation failed Connection reset by peer)
and the next url, it stop.

I don't know how to initialize a new connection. Could you help me please ?

I've try the following solution :
- for every url, I do an HTProfile_newPreemptiveClient("testApp","1.0");
but it failed. The system give a SIGPIPE. 

Thank you for your help.

M. Delaveau