Elucidation is important.

src/conf.py

@@ -625,7 +625,8 @@ registerGlobalValue(supybot.databases.users, 'timeoutIdentification',
     times out."""))
 registerGlobalValue(supybot.databases.users, 'hash',
     registry.Boolean(True, """Determines whether the passwords in the user
-    database will be hashed by default."""))
+    database will be hashed by default.  This only affects new users; users
+    already registered will maintain their current hashedness."""))
 
 registerGroup(supybot.databases, 'ignores')
 registerGlobalValue(supybot.databases.ignores, 'filename',

src/fix.py

@@ -44,6 +44,7 @@ exported = ['ignore', 'reversed', 'window', 'group',
 
 import sys
 import new
+import atexit
 import string
 string.ascii = string.maketrans('', '')
 
@@ -213,7 +214,10 @@ if not hasattr(Exception, '_original__init__'):
         self._original__init__(*args, **kwargs)
     Exception.__init__ = __init__
 
-import atexit
+# Apparently, some things get dismantled a bit early, and we can get stuck in
+# a non-exiting loop because our Exception.__init__ raises an exception.  This
+# makes sure that we replace our __init__ with the original before things like
+# the sys module are dismantled.
 def _replace_original__init__():
     Exception.__init__ = Exception._original__init__
 atexit.register(_replace_original__init__)