Rails 2.1 - when PostsController is present, creating Admin::PostsController fails

Hi,

just found out small problem with Rails 2.1.

If I run a "script/generate scaffold post title:string" that creates
PostsController and later want to make admin controller for it by
running "script/generate controller admin/posts", Rails complain that:
"The name 'Admin::PostsHelper' is either already used in your
application or reserved by Ruby on Rails."

It worked fine in 2.0.2.