PQisBusy() always returns TRUE

Hi,

I'm writing some code for asychronous command processing and I experience
the following problem. Everything seems to be OK (by following the
documentation) until I call PQisBusy(). While PQconsumeInput() returns 1,
PQisBusy() always returns 1! This is the code:

 -------------------------------------------------------------------------
....
// conn is the connection already established in a nonblocking way
//(this is OK, I checked it with sychronous command processing)

    PQsetnonblocking(conn,1);

       //A simple query for now...
    sql = "select * from t1";

    if (PQsendQuery(conn,sql)!=1)
       elog(ERROR,"Something went wrong with PQsendQuery....");

    PQflush(conn);

    sock = PQsocket(conn);

    if (sock < 0)
        break;

    FD_ZERO(&input_mask);
    FD_SET(sock, &input_mask);

    if (select(sock + 1, &input_mask, NULL, NULL,NULL) < 0)
        elog(ERROR,"Nothing comes to my socket!");


       if (PQconsumeInput(conn)!=1) elog(ERROR,"Error in consume...");
    else
    {
        elog(INFO,"OK with PQconsumeInput");

               //Will use a cursor and 'while' later when this
               //will have been fixed...
        if (!PQisBusy(conn))
        {
             res=PQgetResult(conn);
         }
        else elog(INFO,"It is too busy to give me the results!");
       }
...
 -------------------------------------------------------------------------

If I discard PQisBusy the results are retreived without problems.

This code is used inside a SRF that is intended to return tuples from remote
dbs (as in dblink). For the time being I query local tables.
I use v7.4.2.

Is this something too obvious to see it :-) ? Is it something with
nonblocking connection establishment? Any suggestions?

Thanks in advance,
Ntinos Katsaros