I've noticed several instances where an ad, such as the baseball capping contest ad, is linked to a number of other forum features. Blocking an ad can result in forum features, like the 'post reply' or 'start new thread ' buttons (and others, such as almost all the buttons in the reply window), being blocked as well.

Previously, on SBR Odds, I had a similar experience when I blocked an ad. Several functions on SBR Odds, as well as a number of books, vanished. I don't know programming, but this is the only site I know of where blocking ads affects the normal functioning of the site.