basic authentication and proxying

Hello everyone,

I have this weird problem with getting authentication working with
proxying.

I was able to get the authentication working without proxying. I made a
..htaccess file:

AuthType Basic
AuthName UserAdmin
AuthUserFile /home/whittend/sandbox/conf/htpasswd
Require valid-user

In the httpd.conf file:

<Directory /home/whittend/sandbox/UserAdmin/>
AllowOverride All
Options ExecCGI
Order allow,deny
Allow from all
</Directory>

It all works fine until I try to add proxying with a frontend.conf and
backend.conf instead of httpd.conf. Note - the proxy part works fine, it
proxies from port 80 to port 90 on the same IP, but I either get no
authentication happening (and the page gets displayed anyway), or a 403
error without even getting a login screen. Here's the setup with
proxying:

..htaccess:

AuthAuthoritative On
AuthType Basic
AuthName "test UserAdmin"
AuthUserFile "/var/www/conf/htpasswd"
Require valid-user

frontend.conf:

Alias /UserAdmin/ /var/www/UserAdmin/
# the frontend is on port 80 and proxies to port 90
ProxyPass /UserAdmin http://10.8.12.96:90/UserAdmin

backend.conf:

Alias /UserAdmin/ /var/www/UserAdmin/

<Directory "/var/www/UserAdmin">
Options FollowSymLinks
DirectoryIndex index
AllowOverride All
allow from all
# Satisfy any -- note I have tried many combinations here!
require valid-user
</Directory>

If I put the backend stuff in the frontend, and comment out the
ProxyPass - it works. But I need to be able to proxy. I really don't see
what I'm doing wrong.

Any ideas?

Thanks,
Deb