Setup pserver for anonymous only AND block pserver access via username?

[Lummoxx]

I've been trying to accomplish this, to no avail.

I'm offering both ext and pserver access to projects.  I want pserver
to ONLY work for anonymous access, and ext for username access, but
users of the projects are still able to checkout and commit using
pserver and their usernames.

I've read numerous "Permit anonymous read-ony access to your
repository" guides, and have double-checked my setup versus every
single one.  My ext access is fully functional, and pserver correctly
allows anonymous read-only access, but none of the guides that I have
found mention the restriction of username access via pserver at the
same time.

Any assistance appreciated.  Thanks.

Chris