To alleviate the problem immediately it looks like your best bet is to use another browser. I would recommend FireFox. The option of subscribing to InsideFlyer.com and receiving FlyerTalk Premium is also an option as well, with FT Premium you don't see any ads at all in the forums when logged in.

http://www.flyertalk.com/forum/claim_subscription.php

I will also see if there is anything I can do to get the ad changed so it does not get in the way of things in that forum though. Thank you,