Avoid using WordPress and Apache disk_cache extension together … unless you understand what is going on and you now how to fix the problem.

Using both together led one of the sites I have worked on (http://www.gdium.com) to display RSS feeds instead of posts and pages. After a forced refresh of the page (CTRL+R in Firefox) the correct page was displayed. This have been driving me crazy for several days until I actually remembered I had enabled Apache disk caching for another website on the same server.

After disabling disk_cache I did a search and I found someone that was having the same problem which confirmed what I thought.