You have to remember that most people who submit websites to directories are webmasters. The geek crowd doesn't usually click on ads. Your ad placement isn't too bad, but the images look terrible. They don't lineup and are really poor quality. You should try and get more relevant images too. Using some generic icons can work well if done properly!
I know and some are only automatic submission programs. I don’t put adsense on directories anymore.
My directories do fine. I don't know who clicks on the ads but I doubt it's the people listing their sites as the revenue doesn't correlate to submissions - it's the people looking for information.
My directory at BestWebsites.com.my and its Blog are earning OK from Adsense because there are a lot of related articles there. Not purely links to sites.
I used to get nearly $1000 per month from a directory, but a week ago Google killed my site by dropping the SERPs really down. And I even don't know why they did it.