NOW it makes sense. I was writing up a tutorial which involves working with subdomains. I was QAing the tutorial by following the tutorial along but the DNS ch

NOW it makes sense. I was writing up a tutorial which involves working with subdomains. I was QAing the tutorial by following the tutorial along but the DNS changes wouldn't work. I know it worked before but not this time. And meanwhile I was able to visit the websites that I usually visit. After seeing the Comcast letter, I'm concluding that the DNS changes weren't working because of Comcast's issue. I was still able to visit websites because my home DNS server had cached DNS names. Oh well.