jkovar - 12:12 pm on Jun 21, 2009 (gmt 0)

I didn't have any problems at all with the cache: ads.

I tried messing with my preferred language in Opera before going to translate, making sure my Accept-Language header contained only the language I was translating to (es/fr), and still got English ads.

I never thought of using Javascript to detect language before, but considering JS is what Adsense uses to display the ads, I wonder if there's some sort of JS property which isn't related to the Accept-Language HTTP header but instead reads something from the operating system that Adsense uses to determine which language to display ads in.