I've noticed two things with my installation 220.127.116.11 that seem to go screwy.
1. RSS feed. I used Google Reader and I seem to get post shifted to my reader twice and I finally hunted down why. The post time is shifting 3 hours at times when syndication.axd is hit... for example when Google reader first hit my blog it has a publication
date of 18:50 then it will arbitrarily switch to 21:50.
I'm still monitoring this but that is what I saw the first time.
2. Sitemap.axd. It will at times have the www and at times not have the www... why the shift at time? This is from Google Sitemap feature, so it shouldn't have anything to do with how they are viewing the page, they should always be viewing it from the www.