Drafts and archive groups under topics (was: Problem with gnus-topic-display-empty-topics?)

[Lloyd Zusman <ljz@asfast.com>]

> Even though `gnus-topic-display-empty-topics' is set to `t' for me, if I
> select a topic with `RET' or `SPACE', I don't see any of the groups
> within that topic, except those groups containing unread or marked
> articles.
>
> I have to invoke `C-u RET' or `C-u SPACE' on the topic line in order to
> see all the groups within it ... even those groups which are configured
> to be "Permanently Visible" in their own group parameters.

I have figured out more about when behavior occurs:

I have moved my drafts ("nndraft:") and archive ("nnml+archive:") groups
each into their own topics.  In these topics, and in _only_ these
topics, I have to invoke `C-u RET' or `C-u SPACE' to view the groups.
If I invoke `RET' or `SPACE' for these topics, they don't "open" to show
me the groups.

What could be special about `nndraft:' and `nnml+archive:' groups which
would cause this?  Is there a way to cause these types of groups to be
handled the same as all the others, when they are inside of a topic?

Thanks in advance.

-- 
 Lloyd Zusman
 ljz@asfast.com