Different Adsense Ads with and without www in URL

Anyone knows the reason why?

[FromRocky]

I have noticed that the Adsense ads on my sites are showing differently for the same page if the destination URL includes or does not include www. For examples:
1. Some pages show on either www.mysites.com/page1.htm or mysites.com/page1.htm the same ads.
2. Other pages show www.mysites.com/page2.htm with highly targeted ads while mysites.com/page2.htm with the alternate or off targeted ads or other way around.

This behavior has occurred more often since April 1.

Does anyone know the reason or have this kind of behavior?

[valley]

And what about refreshing the page, it seems to bring up different ads in a kind of rotating pattern,
Anyone?

[FromRocky]

I’m so confused! On my webpage about “widget making”, the Adsense shows:

Yesterday:
www.mysites.com/make-widget.htm ----> PSA
mysites.com/make-widget.htm ----> Highly targeted ads

Today:

www.mysites.com/make-widget.htm ----> Highly targeted ads
mysites.com/make-widget.htm ----> Web hosting, nothing relating to the page contents except one word “website” mentioned.

Tomorrow:
Can anyone guess?

This is why the page revenue is going downhill.

What URL destination should be used for Overture or AdWords? Any suggestions?