With the 2005-11-22 builds if you try to access the Authors & Users page in admin you get this error:
Parse error: parse error, unexpected T_STRING, expecting ',' or ';' in /home/beblogger/htdocs/wpmu/wp-inst/wp-admin/users.php on line 308
the solution is escape the " in the string like this:
<td><select name=\"new_roles[{$user_object->ID}]\" id=\"new_role\">";
hope it is useful