Stack traces showing in production mode with consider local off

Hey all,

I have some mongrels running in mongrel service sitting behind apache
on top of Windows Server 2003.

The problem is that in the log files, the request IP address is
showing up as - and so rails is considering it a local
request and displaying the stack traces on errors.

I remember reading about how to fix this somewhere, and I am sure it
is an apache config setting to force the request IP to reflect the
address of the original requestee, not the proxy, but I can't find it!

Any pointers?

All versions of the software are basically current.