Every morning when I check server status,I will find MySQL's password is changed:

mysql -uuser -ppassword 

will report

ERROR 1045 (28000): Access denied for user 'user'@'localhost' (using password: YES)

And then I restart server,and when it's up,MySQL will be back to normal.

It has now become a routinely job.

What can be the cause for this?

How can I know what's exactly happening to MySQL?

Here is the error log:

100122 10:11:16 [Note] D:\MySQL\MySQL Server 5.0\bin\mysqld-nt: Normal shutdown

100122 10:11:16 InnoDB: Starting shutdown... 100122 10:11:18 InnoDB: Shutdown completed; log sequence number 0 22939338 100122 10:11:18 [Note] D:\MySQL\MySQL Server 5.0\bin\mysqld-nt: Shutdown complete

100122 10:12:40 InnoDB: Started; log sequence number 0 22939338 100122 10:12:42 [Note] D:\MySQL\MySQL Server 5.0\bin\mysqld-nt: ready for connections. Version: '5.0.24-community-nt' socket: '' port: 3306 MySQL Community Edition (GPL) 100123 16:20:44 [Note] D:\MySQL\MySQL Server 5.0\bin\mysqld-nt: Normal shutdown

100123 16:20:44 InnoDB: Starting shutdown... 100123 16:20:46 InnoDB: Shutdown completed; log sequence number 0 22939832 100123 16:20:46 [Note] D:\MySQL\MySQL Server 5.0\bin\mysqld-nt: Shutdown complete

100123 16:22:09 InnoDB: Started; log sequence number 0 22939832 100123 16:22:11 [Note] D:\MySQL\MySQL Server 5.0\bin\mysqld-nt: ready for connections. Version: '5.0.24-community-nt' socket: '' port: 3306 MySQL Community Edition (GPL) 100125 9:18:59 [Note] D:\MySQL\MySQL Server 5.0\bin\mysqld-nt: Normal shutdown

100125 9:18:59 InnoDB: Starting shutdown... 100125 9:19:00 InnoDB: Shutdown completed; log sequence number 0 22941001 100125 9:19:00 [Note] D:\MySQL\MySQL Server 5.0\bin\mysqld-nt: Shutdown complete

100125 9:20:22 InnoDB: Started; log sequence number 0 22941001 100125 9:20:25 [Note] D:\MySQL\MySQL Server 5.0\bin\mysqld-nt: ready for connections. Version: '5.0.24-community-nt' socket: '' port: 3306 MySQL Community Edition (GPL)