I updated my WordPress version to Twenty Eleven 3.4.2 and some modifications disappeared. I now realize it is because I didn't create a child theme, so I'm working on one.
The first mod is for the sidebar on this site: http://reddoorreview.com/ I used this suggestion from blaok and it worked perfectly for a 300x220 Google Ad in the sidebar. However, it isn't working in my child theme.
I feel like I'm banging my head against a brick wall.