[BlueOnyx:27104] Why can I not reuse an old username?

[Larry Smith]

Trying to do some account cleanup for a customer
and they have two usernames, that left years ago,
and they want to reuse them but the server says:
"Sorry you have used a value for User Name that is
not available on this system. Please enter another value
for User Name.  The following values are available..."

How do I reuse a username that is not there any more??

-- 
Larry Smith
lesmith at ecsis.net