PQtrace doesn't work

Hello,

I have a little test program (see at the end of the message). The program
crashes when PQTrace is called (instruction xxxx referenced memory at
"0x00000010", the
memory could not be written" (obvious ... )
I use the library libpqdll.lib and postgresql v7.3.4. When I comment the
line the program runs fine.

Any ideas?

gr,

Willem.

#include <stdio.h>
#include <stdlib.h>
#include <libpq-fe.h>
#include <winsock.h>

void main ()
{
int nFields;
int i, j;

PGconn *conn;
PGresult *res;

char *pghost = "linux";
char *dbName = "some_db";

FILE *debug;

WSADATA wsadata;
WSAStartup(0x0101, &wsadata);

conn = PQsetdbLogin (pghost, NULL, NULL, NULL, dbName, "user","");

if (PQstatus(conn) == CONNECTION_BAD)
{
printf ("Connection to database %s is failed\n", dbName);
printf ("%s", PQerrorMessage (conn));
PQfinish (conn);
exit (1);
}

debug = fopen ("trace.out", "w");
--->> PQtrace (conn, debug);

res = PQexec (conn, "BEGIN");
if (!res || PQresultStatus (res) != PGRES_COMMAND_OK)
{
printf ("BEGIN command failed\n");
PQclear (res);
PQfinish (conn);
exit (1);
}

PQclear (res);

res = PQexec (conn, "DECLARE mycursor CURSOR FOR select sum(id) from
relaties");
if (!res || PQresultStatus (res) != PGRES_COMMAND_OK)
{
printf ("DECLARE CURSOR command failed\n");
PQclear (res);
PQfinish (conn);
exit (1);
}

PQclear (res);
res = PQexec (conn, "FETCH ALL in mycursor");
if (!res || PQresultStatus (res) != PGRES_TUPLES_OK)
{
printf ("FETCH ALL command didn't return tuples properly\n");
PQclear (res);
PQfinish (conn);
exit (1);
}

nFields = PQnfields (res);
for (i = 0; i < nFields; i++)
printf ("%-15s", PQfname (res, i));

printf ("\n\n");

for (i = 0; i < PQntuples (res); i++)
{
for (j = 0; j < nFields; j++)
printf ("%-15s", PQgetvalue (res, i, j));
printf ("\n");
}

PQclear (res);

res = PQexec (conn, "CLOSE mycursor");
PQclear (res);

res = PQexec (conn, "COMMIT");
PQclear (res);

PQfinish (conn);

fclose (debug);

WSACleanup();
}