mod_rpaf Nginx Apache – Fix Issues After Ubuntu Upgrade

I'm running an Nginx front-end for static files, and proxying to an Apache backend for PHP and Passenger, using Apache's mod_rpaf to set the correct remote IP address on the backend. Everything worked fine until I upgraded to Ubuntu 12.04 (Precise). Now Apache reports all connections coming from 127.0.0.1.

Here's the relevant configuration. Nothing here changed with the upgrade.

Nginx:

proxy_set_header X-Forwarded-For   $proxy_add_x_forwarded_for;

mod_rpaf:

<IfModule mod_rpaf.c>
    RPAFenable On
    RPAFsethostname On
    RPAFproxy_ips 127.0.0.1 ::1
    RPAFheader X-Forwarded-For
</IfModule>

I'm using %{X-Forwarded-For}i in my Apache LogFormat directive and the access logs are
showing the correct remote address, so I know Nginx is passing the address along properly.

In a phpinfo() test, HTTP_X_FORWARDED_FOR is showing the correct remote address, but REMOTE_ADDR is 127.0.0.1. This is reflected in PHP applications as well, such as WordPress comments.

I've tried switching Nginx and mod_rpaf to X-Real-IP with no effect.

Did something change that I missed?

Relevant version info, everything installed from the Ubuntu repository:

Nginx 1.1.19
Apache 2.2.22
mod_rpaf 0.6