multi drop still don't work

hello i set one bs11 to ts 1, tei 25 and the other one to ts 6, tei 25(also tried 26 with the 2nd), according to openbsc.cfg.2-2. the cabling is also correct, due to a schematic from harald. but the 2nd bs11 not recognised. the funny thing ist, when i configure the 2nd bs11 exactly like the 1st one(the working one, ts 1, tei 25), it don't work. the parameter from bs11_config query are the same like the 1st, but i don't get the abis link up -- Wer Rechtschreibfehler findet, darf sie behalten!