Usually that is not a problem if there is enough optimized content on the page. Sometimes odd things happen. For example, my Weber Internet Marketing site tends to attract "Weber Grills" if I put AdSense on it.

Could you post a link to the page in question so we can have a look?

There can be few reasons why irrelevant ads appear on sites. One reason can be less content on pages, this can result in irrelevant ads.

I suggest you do section targeting which will help to display relevant ads.