RF power problems with current master of osmo-trx

hi, i experience problems with osmo-trx/umtrx. when i start osmo-trx, i get the following output: openbsc osmo-trx # /files/projects/gsm/osmo-trx/Transceiver52M/osmo-trx linux; GNU C++ version 4.5.4; Boost_104900; UHD_003.004.000-1b07671 Config Settings Log Level............... NOTICE Device args............. TRX Base Port........... 5700 TRX Address............. 127.0.0.1 Channels................ 1 Samples-per-Symbol...... 4 External Reference...... Disabled Diversity............... Disabled -- Opening a UmTRX device... -- Current recv frame size: 1472 bytes -- Current send frame size: 1472 bytes -- Setting UmTRX 4 SPS -- Transceiver active with 1 channel(s) i use current master. (an older version with branch umtrx_dual_test works with two TRX.) when i use RSSI test phone, i see that the RF power is high on TS0 and TS1 only. also it takes many tries to sync to it. i receive BCCH infos with some dropouts, but RACH is not received. i have no slotmask define at osmo-bts. any idea what causes it? regards, andreas