[ic] Email address as Unique ID? Having a problem

[interchange-users@icdevgroup.org (Alex)]

We need to use email address as username and be sure it is 
unique. I saw this discussion come up on the list recently 
about how you can enforce this column to be unique by 
editing the profiles.order file. We added the following 
bit of code to IC and it doesn't seem to work for us: 

email=unique userdb: E-Mail address isn't unique

We've tried using this feature with IC 4.9.2 and IC 4.9.3 
without any luck. Also tried adding the code to the 
various profiles: 
checkout_profile 
account_change 
credit_card 
mail_order 

Below is an example used on one of the profiles:
__NAME__ checkout_profile 
fname=required 
lname=required 
address1=required 
city=required 
country=required 
[if value country =~ /^(US|CA)$/i] 
state=state_province 
zip=postcode 
[/if] 
&or phone_night=phone, phone_day=phone Must have day or 
evening phone 
number 
&fatal = yes 
email=required 
email=unique userdb: E-Mail address isn't unique 
email=email


If anyone can point out what we seem to be doing wrong it 
would be most appreciated. We'll be sure to edit the 
responses and give it back to the docs as a tutorial. 

Thanks, 
   Alex