mysql errno 1251 Client does not support authentication protocol requested by server

mysql errno 1251 Client does not support authentication protocol requested by server
OR
unable to connect database server in my php 4.4.9 script.

I have spent some time before found out that php 4.4 isn't compatible any more with mysqld 5.1
Some thought you can find here. Solution of the problem is simple. You must correct user's password and save it in old style.

mysql> SET PASSWORD FOR
    -> 'some_user'@'some_host' = OLD_PASSWORD('newpwd');

Enjoy!