When trying to reset your WordPress blog password, have you seen the following message?

Sorry, that key does not appear to be valid.

This seems to be a bug in wordpress 2.5.1

Basically, it means that password recovery won’t always work and suggests the following workaround based on using phpmyadmin from cPanel in your hosting account. Click on the WordPress database name, and in the row “wp_users” click on the first icon for “browse”. Next, click on the pencil icon for editing the table, then do the following:

User pass > Function > MD5 (encryption) and type in your new password

Finally, click the Go button and you should then be able to login to your WordPress blog.