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.