hmm, why ask this question? adsense on forums and you have forums just for member then it as you see will be from member which they have same ip so if this member click every day will be problem
dont' worry about the forums, when someone clicks on the ad, his ip address (and not that of forum host) is recorded by adsense.
Are you asking about a way to circumvent the click fraud rules? Probably shouldn't do that here if so.
The Big G has a way of working out which clicks are genuine and which are not - as long as you don't click your own ad's - you will be fine!