~QOCIResult: unable to free statement handle

Hi guys

I have a strange problem: I use fedora 12 and an oracle database (v10.2.0.4) and I launch this code:

void DBConnector::
releaseConnection(const dbConnection &dbc)
{
QMutexLocker locker(&mt_connections);

QString conn_id = dbc.getId(); //returns the connection name

cout << "Release Connection: " << qPrintable(conn_id) << endl;
connections.remove(conn_id);
{
QSqlDatabase myDB = QSqlDatabase::database( conn_id );
myDB.close();
}

QStringList test = QSqlDatabase::connectionNames();

QSqlDatabase::removeDatabase( conn_id );
}

But when I execute the code it returns an error: ~QOCIResult: unable to free statement handle. Have you got an idea for solving this problem? I think it is only a warning not a critical error but I want to delete it. I also think it depends on QSqlDatabase::removeDatabase( conn_id );

Thanks

Have a nice day