There is a new court decision of a german court against LH, saying that LH may not refuse passengers to fly the back portion of their ticket, regardless of the use of the first part of the ticket.
It is only a decision of a "Amtsgericht" (AG Erding, decision dated 27.3.07, Az.: 4 C 129/07), so Lufthansa will probably not change their behaviour.
The decision concerns a flight MUC-FLR-MUC. The reason for the decision is that the court thinks that the passenger bought the seat, also on the flight FLR-MUC. If the airline refuses to transport him, they gain an economical advantage as they can sell the seat once more, although somebody has already paid for it. Also the passenger has an unacceptable disadvantage, as he is forced to buy a new ticket, although he has already done so before.
Unfortunately most likely LH will accept the decision in order to avoid a decision by a higher court, which would probably decide the same way.
Here you can find the german text:
http://www.fliegen-sparen.de/cms/new...47_meldung.php