finally I managed to book my flight to DebConf8.
2008-08-03 IB3537
07:45 / Munich, Franz Josef Strauss, Terminal 1
10:25 / Madrid, Barajas, Terminal 4
2008-08-03 IB6845
12:25 / Madrid, Barajas, Terminal 4S
19:40 / Buenos Aires, Pistarini, Terminal A
2008-08-25 IB6844
21:35 / Buenos Aires, Pistarini, Terminal A
14:30 day +1 / Madrid, Barajas, Terminal 4S
2008-08-26 IB3564
16:30 / Madrid, Barajas, Terminal 4
18:55 / Munich, Franz Josef Strauss, Terminal 1
& I'm still surprised how frequently the prices for the same flights
change ...