OK, rather delayed as I had some non site-related issues keeping me away from looking at this, here's another probably cache-related weirdie FAO Lazeez:
Having used my full quota, a refresh of the home page before the counter reset time (as read from the todaysAccesses page) gave the expected count of 16/16, and the yellow banner stripe "You have accessed 16 Stories. You must wait: ..." at the top of the home page. Subsequent reloads up to the counter reset time correctly gave decreasing wait times, but on reloading after the counter reset time gave THE SAME MESSAGE with INCREASING times each reload until about a half-hour after the counter reset time (which happened to be the first time I left more than 5 min between reloads). During the count-up phase the todaysAccesses page was showing the original counter reset time (in the past by then), and all of the previous downloads. The correct 'No stories in recent list' was shown after the half-hour or 5-min gap in reloads. Worthy of note is that during this count-up phase a new item was shown on the homepage stream. I respectfully suggest that the counter reset time should trigger an invalidation of the user cache to fix this.