Hello,
Sorry for late answer.
You can do it with smarty Box Type
Put Google Adsense code to the box content, but wrap your code with {literal} tags, prevent smarty compiling issues.
{literal}
your code here
{/literal}
And i think better to disable Box Style for the adsense blocks.
Better and more convenient management for ad blocks and banners via banners plugin, for 3.2 it exists already and for 4 version will be ready soon.