[Serusers] Register problem

Hi, I installed SER on a new system and now I can't REGISTER anymore. With a little bit luck, the users can REGISTER after a restart of the system, but the register expires and the user is unregistered for ever. SER sends back a Unauthorized, although the user is registerin correctly. It's a phenomenon that I don't understand. May be the database? Here's a log of the database: Sep 26 18:00:22 pbx5 postgres[286]: [13-1] LOG: 00000: statement: BEGIN Sep 26 18:00:22 pbx5 postgres[286]: [13-2] LOCATION: pg_parse_query, postgres.c:464 Sep 26 18:00:22 pbx5 postgres[286]: [14-1] LOG: 00000: statement: select userpass,rpid from subscriber where username='43750' Sep 26 18:00:22 pbx5 postgres[286]: [14-2] LOCATION: pg_parse_query, postgres.c:464 Sep 26 18:00:22 pbx5 postgres[286]: [15-1] LOG: 00000: statement: COMMIT Sep 26 18:00:22 pbx5 postgres[286]: [15-2] LOCATION: pg_parse_query, postgres.c:464 Sep 26 18:00:22 pbx5 postgres[307]: [25-1] LOG: 00000: statement: BEGIN Sep 26 18:00:22 pbx5 postgres[307]: [25-2] LOCATION: pg_parse_query, postgres.c:464 Sep 26 18:00:22 pbx5 postgres[307]: [26-1] LOG: 00000: statement: select userpass,rpid from subscriber where username='43750' Sep 26 18:00:22 pbx5 postgres[307]: [26-2] LOCATION: pg_parse_query, postgres.c:464 Sep 26 18:00:22 pbx5 postgres[307]: [27-1] LOG: 00000: statement: COMMIT Sep 26 18:00:22 pbx5 postgres[307]: [27-2] LOCATION: pg_parse_query, postgres.c:464 Sep 26 18:00:22 pbx5 postgres[282]: [10-1] LOG: 00000: statement: BEGIN Sep 26 18:00:22 pbx5 postgres[282]: [10-2] LOCATION: pg_parse_query, postgres.c:464 Sep 26 18:00:22 pbx5 postgres[282]: [11-1] LOG: 00000: statement: select userpass,rpid from subscriber where username='43750' Sep 26 18:00:22 pbx5 postgres[282]: [11-2] LOCATION: pg_parse_query, postgres.c:464 Sep 26 18:00:22 pbx5 postgres[282]: [12-1] LOG: 00000: statement: COMMIT Sep 26 18:00:22 pbx5 postgres[282]: [12-2] LOCATION: pg_parse_query, postgres.c:464 Sep 26 18:01:00 pbx5 postgres[332]: [19-1] LOG: 00000: statement: BEGIN Sep 26 18:01:00 pbx5 postgres[332]: [19-2] LOCATION: pg_parse_query, postgres.c:464 Sep 26 18:01:00 pbx5 postgres[332]: [20-1] LOG: 00000: statement: delete from location where username='43750' AND contact='si p:43750@xxx.xxx.xxx.xxx:63713' AND Can anyone of you help me?? Thanks!!! Sebastian