I am logged in in Firefox, not in IE7, not in IE6. What I did in IE6 and IE7 was to enter the page and view source. No log-in, no comments. Allow to me to take advantage of your kind help to ask some more questions:
1. What determines when to invalidate the cache? I understand when a comment is posted, that makes sense, but I've seen pages being invalidated despite no comments were posted. Example this morning I scheduled an article at 04:00, I entered the page at 09:30 and the timestamp was indeed 09:30.
2. I am on IIS6 and the settings page is saying "Mod rewrite may not be installed!". What exactly is this? Permalinks are still working properly and caching is in place.
3. Lock Down. Apologies if a stupid question but what exactly does this feature do? I have occasions when I get 2,000+ hits in a matter of seconds on a particular article. What I was going to do is to disable comments, so as to be 100% sure that the page is always retrieved from the cache. Is Lock Down a "similar" feature?