Adsense displays ads not related to content

Hi:

I'm still new to WPMU. Ver 2.8.4a with Supporter and Ad Sharing Plugin.

The issue is that Ad Sharing displays ads in posts and pages as expected. However, displayed ads are not related to the content of posts and pages. Displayed ads are mostly related to WordPress, or WP Themes, WP Freelancers, etc. We are using a theme called Lux House 1.0 by qualitywordpress found here http://www.qualitywordpress.com/?p=107

Also, ads are displayed in English, but the whole site is written in Spanish.

How can I solve these issues?

What I am doing wrong?
Thanks.