Please make sure you request from Google only ads that are 250 x 250 pixel squares. To do this:
Go to your AdSense account, click on the “My Ads” tab.
In the “Content” area (see the left of the page), click on “Ad units”.
You should see a list of existing ad units (it may be blank), above which there’s a button saying “New ad unit”. Click on that button.
Using the “Size” pull-down menu, select “250 x 250 square”. It’s in the “Other – Square” portion of the pull-down menu.
Complete the ad creation process by following Google’s instructions, and then, copy/paste the code Google created into a blank document (you only need the pub-ID and slot ID but Google doesn’t let you copy/paste only a portion of the ad code).
Log into your KnowABit account.
At the top left, click on “Dashboard” and then on “My Google AdSense” in the pull-down menu.
From the document you opened, highlight and copy your pub-ID number (that’s the one that has “pub-” followed by a bunch of digits). Make sure you grab all the characters including “pub-“.
Paste your pub-ID number into your KAB Google AdSense where it says “Your Advertising ID”. If you’ve already entered your AdSense information before, you should already see it there, in which case you do not need to re-enter it.
From the document again, highlight and copy your slot ID number (that’s the one that has just a bunch of digits).
Paste your slot ID number into your KAB Google AdSense where it says “Google Ad Slot”.If you’ve done this before, you should see your old slot ID there – make sure to replace it with the new one.
Don’t forget at this point to click “Save changes” at the bottom left of the KnowABit page where you’ve entered the new AdSense information.