Wifi on board of KLM?

I am writing this blog entry while on a KLM flight from Shanghai to Amsterdam. The flight is excellent: I booked economy class but got upgraded to business. So I am sitting on the upper deck enjoying the spacious seats. After becoming an entrepreneur I almost always fly economy, but I have to say that business class makes such long flights (almost 12 hours) much more enjoyable and much more productive. I slept for a couple of hours, read two Dutch newspapers and three magazines, plus prepared a presentation.

While working on my laptop I suddenly got a message that a wireless network was available. I was surprised, because I thought KLM was a bit behind other airlines in this respect. I connected to the network (I planned to give my parents a call over Skype), but was not able to get onto the internet. I suspected I might need a password, so I asked a stewardess. She told me there is no wifi on board, so I showed it to her. She looked at the screen, then at me and then immediately called the cockpit. She took my laptop to the flight deck (I was not allowed to go) and discussed it with the captain. He had no idea what it was, and said he had never seen this before. Well, I don’t know either, but the signal was quite strong, so there must be something on board. The stewardess asked me a couple of more questions (Were you trying to connect? Yes, of course. What else did you do? Nothing, just clicked on the available network), but then left it at that. The signal was still there when she left, but a few minutes later it was gone. Anybody any idea what might have caused this?