Adsense problem with two languages on one webpage

The quest for content continues. Another blog post went up just now and I have created a new section on the site that will hold Spanish quick reference resources. I will be spending the next two hours of Sunday afternoon adding to two existing pages with the help of a native Spanish person to do some copy checking for me.

One possible problem I have noticed with a site that contains two languages, is that Google is serving me adsense ads in Spanish and English. My target audience will be English speakers, but they will have a certain level of Spanish too so I am not sure that this turn of events is entirely a bad thing. I have tried the technique of adding the HTML section pointers to hi-light the sections of text that I want Google to take into account when they choose the ads to serve on my pages.

It's a simple thing. Just add <!-- google_ad_section_start --> at the start of a relevant section and <!-- google_ad_section_end--> at the end of it. Hopefully Google will pay attention. They say it takes a few days to take effect.