jdk1.5下用javaw.ext可以运行， 用java.exe运行就提示连不上mysql？

我在jdk1.4.2下做过的一个项目，当时用java.exe和javaw.exe都能运行的。 昨天把C盘格了换成jdk1.5了，用javaw.exe运行那个程序还好用， 可是用java.exe就不能运行了。 是1.5什么地方改了？ 还是我哪出错了？ 求教。

这是连数据库代码：

package db;
import java.sql.*;
import java.io.*;

public class ConnectionDB
{
int rsud;
ResultSet rs;
Connection con;
Statement stmt;
ResultSetMetaData rsMetaData;

public ConnectionDB()
{
try
{
Class.forName("org.gjt.mm.mysql.Driver").newInstance();
con = DriverManager.getConnection("jdbc:mysql://localhost/yeekong?user=dayang&password=dayang");

stmt = con.createStatement();
}
catch(...){...


提示如下：
java.net.SocketException: Socket is not connected: connect
at java.net.PlainSocketImpl.socketConnect(Native Method)
at java.net.PlainSocketImpl.doConnect(PlainSocketImpl.java:333)
...
at org.gjt.mm.mysql.MysqlIO.<init>(MysqlIO.java:114)
at org.gjt.mm.mysql.Connection.<init>(Connection.java:229)
at org.gjt.mm.mysql.Driver.connect(Driver.java:126)
at java.sql.DriverManager.getConnection(DriverManager.java:525)
at java.sql.DriverManager.getConnection(DriverManager.java:193)
at db.ConnectionDB.<init>(ConnectionDB.java:34)
at db.ConnectionDB.main(ConnectionDB.java:67)
SQL Exception: Cannot connect to MySQL server on localhost:3306. Is there a MySQL server running on the machine/port you are trying to connect to ? (java.net.SocketException)