You site suggestion has only been received if you get the "Thank you for your suggestion" screen. Anything else and it hasn't gone through.
We believe that there is a bug that means if you fail a particular captcha image on the first attempt, that image will never work for you even if you enter the correct text on a subsequent attempt. Instead, go back to the form and use the refresh button to get a new image. Some browsers will keep the details you've entered, some won't (so you might want to save them first).
We've informed AOL staff of this problem some time ago, and they are atill (apparently) working on it.