Recent versions of MySQL have changed how the 'password' function works. While the function originally returned a 16 character hash of the password, it now returns a 41 character hash of the password. The 'User' table only allows for 16 characters for the password, and thus the password hash is getting truncated. As a result, no one is able to log in using any password when using the current version of Extend-A-Story with the current version of MySQL.
This thread provides more details and a workaround: http://www.sir-toby.com/phpbb/viewtopic.php?t=1091
I have committed the fix for this bug into Git. The fix will be included in the next release of Extend-A-Story.
The fix for this bug has been included in Extend-A-Story version 2.2.0.