It should work OK now. Google often can't supply ads for the most recent threads as it takes a while to react. In the space the sponsor's ads appear - Flecktarn, NAAFI Financial etc. The sponsor thing on the left doesn't really apply to google, but it helps mark it out.
Ona similar subject I've been desperately trying to make the wierd and wonderful google links a bit more relevant - I was sick of seeing adverts for USMC whites and US defence manuals! Sometimes it gets it bang on though - the tribute to tony blair advert that appears whenevr our leader's name is mentioned makes me laugh. Even google search bit things have a sense of humour.
I didn't put them there, so I am not sure how they came to be in my hosts file. As a result I now don't see any ads from google on Arrse either at the top or bottom of threads, but I used to see them at the top of pages.