For the last few days whenever I and others at the office do a Google search, we get redirected to google.es. I noticed today that I'm seeing Google Ad Sense ads in Spanish as well. I don't think it's something on my configuration, machine, or profile because it only happens at the office and happens to others as well.

The office IP is 74.81.253.227 which Maxmind thinks is in Utah (because it is). But assuming that Google is making the decision based on GeoIP, they clearly don't.

Does anyone know whether Google is indeed making these decisions based on GeoIP and how you can correct their data once they get it wrong. Updating the "preferred language" and other preferences doesn't make any difference. You can force Google to go to the .com site, but it only lasts for a single session then you're right back to google.es and Spanish language ads.