LH is a crazy airline they always “improve” something: One time Miles & More , another time their timetable : Sometimes LH offers only two service classes, sometimes "new" Biz seats ^ ^ ^ , sometimes only flights on specific days, they change their rotation and so on:

Until March 26th 2005 LH did:
LH 726 & 727 MUC-PVG-CAN-PVG-MUC
LH 744 & 745 FRA-BKK-MNL-BKK-FRA
LH 778 & 779 FRA-SIN-CGK-SIN-FRA

From March 27th 2005 LH offers:
LH 776 & 777 FRA-SIN-FRA
LH 778 & 779 FRA-BKK-CGK-BKK-FRA
LH 788 & 789 FRA-CAN-MNL-CAN-FRA

No changes:
LH 772 & 773 MUC-BKK-SGN-BKK-MUC
LH 782 & 783 MUC-BKK-KUL-BKK-MUC

If I were you, I would stick to LH and do my pit stop in the City of Angels at BKK. There are also decent shops and in the very near future their location change to Suvarnabhumi