请问windows下用Navicat能连，用PHP无法连接远程mysql的有关问题！

请教windows下用Navicat能连，用PHP无法连接远程mysql的问题！急！！！

PHP code

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$user="user_test";
$pass="12345";
$server="172.17.1.15";
$port="3306";
$con=mysql_connect($server,$user,$pass);

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PHP版本是 5.3 Mysql版本是 5.077 使用IIS7

显示的是如下错误：
Warning: mysql_connect(): Premature end of data (mysqlnd_wireprotocol.c:554) in D:\WwwRoot\AutoDial\mysql_connect_test.php on line 7 Warning: mysql_connect(): OK packet 1 bytes shorter than expected in D:\WwwRoot\AutoDial\mysql_connect_test.php on line 7 Warning: mysql_connect(): mysqlnd cannot connect to MySQL 4.1+ using the old insecure authentication. Please use an administration tool to reset your password with the command SET PASSWORD = PASSWORD('your_existing_password'). This will store a new, and more secure, hash value in mysql.user. If this user is used in other scripts executed by PHP 5.2 or earlier you might need to remove the old-passwords flag from your my.cnf file 

奇怪的是，使用 navicat可以连接到mysql，但使用代码不行，想请问下该如何解决啊？！谢谢各位了！

------解决方案--------------------
自mysql 4.1开始，不能再用明码的password连接mysql，你上面至少涉及这个问题