well, ad-hoc networks, created e.g. with an iphone or some other phone, certainly don't show up in wifi settings, but this is usual android behaviour as far as i know. they show up in wifi manager app, but i can't connect to them, even with static ip, as it's described in some possible solutions like the one you posted before.
well, my sailing trip, where i need such access, because during sailing we use an old windows mobile samsung omnia as a 3g wifi router, is unfortunately slowly coming to an end, and back home i won't be having this problem anymore
thanks for your help!