"warning: array_fill() [function.array-fill]: Number of elements must be positive in .. database.inc on line 241"

When viewing any node NOT authored by 'admin' as 'admin' (only) I get the following ERROR message:

    * warning: array_fill() [function.array-fill]: Number of elements must be positive in 
... /drupal/includes/database.inc on line 241.
    * warning: implode() [function.implode]: Invalid arguments passed in /Library/WebServer/Documents/drupal/includes/database.inc on line 241.
    * warning: array_keys() [function.array-keys]: The first argument should be an array in 
.../drupal/modules/user/user.module on line 500.
    * user warning: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near ')' at line 1 query: SELECT p.perm FROM role r INNER JOIN permission p ON p.rid = r.rid WHERE r.rid IN () in .../drupal/modules/user/user.module on line 500.

Strangely, it does not seem to happen the other way around as an authenticated user when viewing a node created by 'admin'.
(And I checked the logs also.)

Also, it does not happen on views or other dynamic pages, only on content nodes,
presumably on those where the extra [add child] pulldown menu is generated.

It is definitely provoked by BookMadeSimple, I've experimented with enabling/disabling the module to isolate it as the cause.

I really like this module (and thanks for the work on it) and I hope you can investigate the problem.