I just went back through some post records. You and Mew share the same ISP leading me to believe it was something at the ISP level. Caching differences could explain why it worked on your brother's computer and not yours.
We have a really kickass new log monitoring tool. I did a bit of forensic analysis and found nothing amiss, so unless this becomes a widespread issue (outside of both your ISPs) we'll chalk it up to ISP flukes and call it closed.