Posted by The issue, if anyone is interested, has to do with the plugins folder itself. When you upload the adsense-deluxe folder you cannot have adsense-deluxe.php in its own folder. The folder that adsense .8 comes in is called adsense-deluxe_wp_plugin_v0.8, and I uploaded the folder, leaving adsense-deluxe in its own directory, which is how all my other plugins are instructed to be installed. But not this one.You have to upload just the adsense-deluxe.php file to the wp-contents/plugins folder. If you do not do this, and instead place the adsense-deluxe.php file in its own nice little folder, then you WILL be able to activate it, but you will NOT be able to ever configure it. Ever.So, make sure that adsense-deluxe.php gets uploaded all by itself to the plugins folder. Leave it out in the open, exposed inside the plugins folder. DO NOT place it in its own folder or it will not work.
From: http://wordpress.org/support/topic/97912
一直听说adsense-deluxe很牛B，为了冲击GGAD的100美元，我就想装上看看效果。可就是这个插件最有个性，添加广告总不成功，显示“Cannot load adsense-deluxe.php”。
先google搜索，后测试验证才知adsense-deluxe.php必须放在“/wp-content/plugins/”根目录下，而不是之前的“/wp-content/plugins/adsense-deluxe_wp_plugin_v0.8/”。
great helpful post..