hmm your bandwidth has exceeded at the moment so I can't really take a look at your boards at the moment. But is your pages optimized, also not making enough money could be due to the part that the ads are not placed in a correct position that someone would consider clicking? Also create channels so that you will know where that money is coming from, that way you can target that area even more. Also keep yourself updated here
http://adsense.blogspot.com/, some nice articles there that could help you.
My last recommendation is that if your site is really that big and is getting all that traffic, why not get advertisers that would advertise at your site directly and that you can charge them on pay per click or impression basis.
Good luck.