success!
Today I tried it again, just for the sake of it, expecting an empty Connection window as always. But this time all iPads running Lemur did appear in the Connection window.
There has been some fundamental changes in my environment since I've started this thread. I try to describe them in detail, so that I can find out what the cause was for the earlier unsuccessful attempts.
1. I use a modern model of router instead of older laptops with older network cards and ad-hoc. But I assume this isn't relevant. Just mentioning in case it is.
2. iOS 6. Before it was iOS 5, but although Apple changed quite a bit concerning WiFi, I also don't think it is relevant.
3. I use similar IP addresses on iPads, router, and computers (192.168.1.x). Only the 'x' value is different. Before I used entirely different IP addresses on my iPads. My guess is that this was the reason why I couldn't connect to the editor on the Mac.
Problem solved, but I don't exactly know how and why. Still leaves some sort of uneasiness, I would like to know for sure. For being able to solve other people's connection problems (that still exist), and of course to solve mine if new ones may occur.
I don't have a Macbook, therefore I can't say anything about ad-hoc. With older Windows laptops and iOS 6, ad-hoc is no more usable.
And it is a fact that no-one is able to help you in such a case. I find this rather frustrating. So many people using wireless technology, but no usable advice, even is specialised forums like Neyrinck, Hexler, Liine, and others. Without a single exception, I
always had to solve WiFi connection problems by myself! I come from the analog world. If someone had a connection problem and described it in readable language, I could always give the solution without even seeing the setup. In WiFi-network land, I'm not able to do this. I'm just happy if it works at my place, and I spend countless unpaid hours to make it work. Computer networking is still an enigma to me, although I use it since a decade and everything is fast and perfectly working now. Network rendering in CAD, video, and MIDI, OSC, file transfer. But I'm far from being an expert. In the analog world, I've become an expert in a year or two. It's easy once you learn some principles. In network world, there are principles too, why is it so difficult compared to analog connections?
I hate connection problems. They are so useless. There should be easy answers so that nobody wastes time for any setup.