To answer it we would need to know exactly what he means. As people have stated, as long as it is not contextually relevant it may be ok - however, we dont know what he means, and can't give him the right answer until he clarifies the request.
Yes, you can have another pay per click advertiser on your pages alongside adsense, as long as its not contextual.
Cripes how can you people understand what he's asking? I've read it 10 times and I still can't make heads or tails of it.
Seems to me that if you want to use adsense you must always 'err' on the side of caution. Google appear to pull the plug on Adsense accounts when your**interpretation** of their TOS is different to theirs... and the publisher has no right of appeal. I.M.H.O the only safe way is to have both purely Adsense sites and sites with other advertisers/affiliate programs...never mix the two.