I have recently become unable to login as admin. The problem seems to be that a correct login resets the user_pass field in the wp_users table. For example, I can manually set the value to "5f4dcc3b5aa765d61d8327deb882cf99", which is the md5 hash of "password" by using an UPDATE query (and verify with select). I can go to the wp-login.php screen and enter the username admin and password "something". I will be greeted with two "ERROR: Invalid password" messages and will be asked to login again. If I supply the correct password "password", I will be asked to log in again without any errors or warnings and, however, a SQL query will show that the user_pass for admin is now set to "$P$BOmBjkppZTzvS13ER4GIbBrrW.e22P1". I have tried upgrading to 2.6.2 (even though the readme.html in wordpress-2.6.2.zip says it is 2.6.1) and have rebuilt the wp_users table from an older backup without any resolution. Please let me know if you have any pointers to resolve this. Thank you in advance.