Ads within the top and bottom limits of the forum page affect user flow, without those ads all the buttons/links are easily accessable without interuption from the ads. I use the links and shortcuts both top and bottom and when the ads are outside the user's area it makes for a better flow.
The footer ad that was there this morning definately did the job it was intended to....it was in your face and we may not have bitched so much IF it was electronic related.
You have to make a living Dave, do as you must.