Any directory on my RHEL4 server running the latest RedHat Apache 2 RPM that doesn't contain an index.* file is throwing back a 503 error rather than listing the contents of the directories for all virtual hosts.
As far as I can tell all Apache conf files are set correctly Allowoverid, Indexes and any other directives I can think of.
The error logs and access logs don't show me anything odd other than a 503 error being returned.
I'm also not entirely sure when this started happening, could've been when I last updated the RPM, but I've also been tweaking my mod_security rules, but I have NO outgoing rules (and no rules set to return a 503 at all) that I know of, so I don't think it's that.