google ad sense stopped working

Hi,

I have a site and the google ad sense stopped working. I went to google and got new code, but it was very similar to the old one. Just the id changed. It seems like the javascript isn't being read. I'm not sure what happened. I have the code in a block that has php set as the defualt. Before it ran fine. Also on other sites it runs fine. So i'm not sure why all of sudden it stopped working. Maybe I upgraded a module and didn't notice.
I'm not sure. Has this happened to anyone?

Antonio