mysql问题

我的一台机子，源码装的能正常启用
安装 MySQL:

shell> groupadd mysql
shell> useradd -g mysql mysql
shell> cd /home/soft/
shell> tar -zxvf mysql-4.0.tar.gz
shell> cd mysql-4.0
shell> ./configure --prefix=/usr/local/mysql
shell> make
shell> make install
shell> cd /usr/local/mysql/bin
shell> ./mysql_install_db
shell> chown -R root /usr/local/mysql
shell> chown -R mysql /usr/local/mysql/var
shell> chgrp -R mysql /usr/local/mysql
shell> cp /usr/local/mysql/share/mysql/mysql.server ./
shell> chmod 711 mysql.server

shell>./mysql -u root -p 能正常进入
但是不能改密码，我的命令是
./mysqladmin -u root -p oldpassword password newpassword
然后在次输入newpassword
出现以下提示
Can't connect to MySQL server on 'localhost'
说连不上机子，
但我phpmyadmin，都能连上的呀？
./mysql -u root -p password 也能正常进入操作的
这是什么回事？　　　　　　

知不道