Corrupt Directory Permissions

[Phil Jones]

Hi all

New to the list - hoping someone can shed some light
on a recurring problem we are having. 

Running RedHat on a Cobalt RAQ4 server (web server) and
finding that from time to time seemingly random directories 
have their permissions corrupted so that the leading 'd'
ss replaced with a '?' - meaning that we can no longer access
any files within the directory and the only option is to
delete and restore from backup.

Does anyone have any idea what may be causing this (has 
anyone ever observed a similar problem?) and is there perhaps
a method of repairing such corruption.

Pulling my hair out here - any help/advice greatly appreciated.

Phil Jones