[support] Can't add user in D6: illegal choice

[Luke]

Hello

I have been a user of D5 for quite some time, but because a somewhat 
urgent project requires features which it doesn't have, I'm playing with 
D6.10 and filefield_sources.

 I receive the following error when trying to create a user:

An illegal choice has been detected.  Please contact the site 
administrator.

Well, that's me, and I've not a clue.

I did get the following error, while trying to add a node of a type I 
created.  The type has a filefield field associated with it, into which I 
had uploaded a file, and this happen on save:

     * warning: array_merge_recursive() 
[function.array-merge-recursive]:
       recursion detected in
       /home/webusers/.../drupal6/includes/module.inc on line 473.

I have no idea what factors might be involved here, as this is the first 
node of any content type which I have added, and the first user after the 
administrative account.

I'll pull D6 and start from scratch if I have to, testing as I go, but I 
thought I'd ask here first.

The modules at play are:

advanced_help  filefield_paths    imce        transliteration
cck            filefield_sources  mimedetect  views
filefield      getid3             token

Oh, the getid3 module is currently broken, because it can not find the 
main library on which it depends, on my Ubuntu system.

Luke