No protocol handler was valid? (Apache config problem)

Well, I'm trying to get my first deploy up. I'm developing using 1-
click against a legacy (SQL Server) database. Deployment is to RHEL
5.

I am following the deployment recipes in the book. In particular, I
copied (with necessary changes) the stuff for http.conf. I'm getting
permission denied errors, and /var/log/httpd/error_log has this to
say:

[Thu Feb 14 14:14:11 2008] [warn] proxy: No protocol handler was valid
for the URL /subproject. If you are using a DSO version of mod_proxy,
make sure the proxy submodules are included in the configuration using
LoadModule.

Everything else looks pretty quiet and/or expected. The curl test in
the book passes. The / default page is still in place, and renders no
problems.