I think you will find most do not. You could go through this list and check: http://www.forumdr.com/free-forum-hosts/211/
i don't know about lefora and zeta but for forumotion when i used i created block for placing my ads and my forum is not closed by them i had know many forum abuse their TOS but they did'nt close it maybe because tons people use their service
Thanks for the info. Do you mind explaining to me how exactly I can insert my ads? What's a "block"? Thanks!!
by creating a div html code and place ads code within that's i called a block if u know html it is easy to insert your ads
This philippine news forum is using an SMF forum software and it has Google adsense ads. You can install SMF using Fantastico in cPanel from your webhost.
For SMf though you need to find your own host. Free hosts exist but you'd have to look into each one's policy on allowing google ads, because the free hosts themselves use ads to support the service.
http://f0rums.com is completely free and rid of ads. You're also welcome to put your own adsense code inside the forums. You choose your own subdomain like http://music.f0rums.com