[Users] errors when making a call!

Hi all When imake calls, signalisation goes well but, when, i hang up my client, i have no voice in any client! And my openser server display methese errors: 0(4335) lookup(): Error while extracting address of record 0(4335) ERROR: parse_uri: uri too short: <sip:> (4) 0(4335) ERROR: parse_sip_msg_uri: bad uri <sip:> 0(4335) WARNING: do_action:error in expression 0(4335) ERROR: parse_uri: uri too short: <sip:> (4) 0(4335) extract_aor(): Error while parsing Address of Record 0(4335) lookup(): Error while extracting address of record 0(4335) Warning: sl_send_reply: I won't send a reply for ACK!! 0(4335) force_rtp_proxy2: incorrect port in reply from rtp proxy 0(4335) force_rtp_proxy2: incorrect port in reply from rtp proxy 0(4335) force_rtp_proxy2: incorrect port in reply from rtp proxy 0(4335) force_rtp_proxy2: incorrect port in reply from rtp proxy 0(4335) force_rtp_proxy2: incorrect port in reply from rtp proxy 0(4335) force_rtp_proxy2: incorrect port in reply from rtp proxy 0(4335) ERROR: parse_uri: uri too short: <sip:> (4) 0(4335) ERROR: parse_sip_msg_uri: bad uri <sip:> 0(4335) loose_route: Error while parsing Request URI 0(4335) ERROR: parse_uri: uri too short: <sip:> (4) 0(4335) ERROR: parse_sip_msg_uri: bad uri <sip:> 0(4335) WARNING: do_action:error in expression 0(4335) ERROR: parse_uri: uri too short: <sip:> (4) 0(4335) extract_aor(): Error while parsing Address of Record 0(4335) lookup(): Error while extracting address of record 0(4335) ERROR: parse_uri: uri too short: <sip:> (4) 0(4335) ERROR: parse_sip_msg_uri: bad uri <sip:> 0(4335) WARNING: do_action:error in expression 0(4335) ERROR: parse_uri: uri too short: <sip:> (4) 0(4335) extract_aor(): Error while parsing Address of Record 0(4335) lookup(): Error while extracting address of record 0(4335) force_rtp_proxy2: incorrect port in reply from rtp proxy 0(4335) force_rtp_proxy2: incorrect port in reply from rtp proxy How can i fix those errors? Thanks for help Serge