moderators-
Please delete this post if I am totally wrong. If I am right, though, this may be the cause of a lot problems people have with looping.
Redirects in a RewriteRule create a new request. As such, it gets sent back through all the rules. Thus, the [L] flag does not work on redirects, it only works on rewrites.
Rewrites in a RewriteRule change the current request, so the [L] flag will work to stop processing.
comments on this?