prova così:

codice:
PV_sql = "INSERT INTO Statistiche (Date,Url,IpAddress,Referer,UserAgent) " +
            "VALUES(" +
            "#" + Year(System.DateTime.Now)&"/"&Month(System.DateTime.Now)&"/"&Day(System.DateTime.Now)
) + "#," +
            "'" + Request.ServerVariables["URL"] + "'," +
            "'" + Request.ServerVariables["REMOTE_ADDR"] + "'," +
            "'" + Request.ServerVariables["HTTP_REFERER"] + "'," +
            "'" + Request.ServerVariables["HTTP_USER_AGENT"] + "')";