Ads do not appear inner page?
 

Hi guys, i have a interesting problem. i insert two google ads to forum sidebar. its working fine on forum homepage.but ads do not appear inner page. let me show you ;

here is our forum:

http://www.oyunfest.com/forum

in the home page, ads(2) appear on the right.now please click any forum page.here is a interesting problem. one of the ads is lost. now please click again any thread. here is a new interesting problem :D all of ads on the left is lost. but if you wait a minute, ads will appear automatically.

how can i fix this?

can anybody help us?