This was a mail that I received not more than one day ago about an upcoming changes to Google policies about the inability to make any changes to your adsense on relevant google sites like bloggers e.t.c.
This change shall take effect starting August ending 2013.
Read the excerpts here"
We’re writing to let you know about some
important changes that will be happening to AdSense on Google Sites. Starting on August 30th, it will no longer be possible to make updates to AdSense on your Google Site.
Any ads that you currently have running will not be altered or
removed. However, it will no longer be possible to edit or add new ads
to your existing site or new pages.
This change does not require any action on your part and will not affect the current implementation of ads on your site.
To read more details about this change, please visit the help page.
The Google Sites Team
So if you need to make any changes to your adsense account ads...you can still do it now
while you can. The reposition of ads,change of formats and styles e.t.c as it would suit your visitors.best! Make them NOW!