The thing is, this is my friends blog and she only signed up for Adsense two days ago. Do you think it's because I'm generating the code with my account and then changing the publisher id in the code?
Please tell her to check inbox. If your friend hasn't got one, try to place adsense code on other sites and see if is will be displayed or not. If it works, then the adsense has been prevented from being displayed on specific website. Your account not banned but it is like a warning. I had experienced this one when I have tested on placement and found the adsense had disappeared from website but only one, others is works.
You can see the ads on every page but you can't see it in homepage. the allowed ads per page and per type is only three. so if you place your ads after your post and you have more than 3 post in homepage, definitely, the ads will not going to appear on your site.