Quoting Jan Steinman, from the post of Wed, 23 Mar:
Have you tried using Alias instead of RewriteRule?
I tried both under 1.4b5, and found Alias was slightly faster, and MUCH easier to understand. The RewriteRule technique may have some advantage I don't understand, which probably means I don't need it!
well, it is definitely faster and offeres less pitfalls than the all-powerful mod_rewrite, but there's one thing it won't do (correct me if wrong!) - it won't let you use page names in the root, i.e. get rid of the /w/ or /wiki/ or what have you. I think I raised that once.
I'm not saying your setup is bad ofcourse, it's a misfeature in Apache...