[Serusers] ser+sems t_write_unix error !

I have: Sems downloaded from: http://www.iptel.org/drupal/sems Ser version: 0.9.6

in ser.cfg: unix_sock="/tmp/ser_sock" sock_mode=0666 fifo_db_url="mysql://ser:user@server/ser" fifo_mode=0666 ........ if(!t_write_unix("/tmp/sems_sock","conference")) .... ...

in sems.cfg: socket_name=/tmp/sems_sock reply_socket_name=/tmp/sems_rsp_sock ser_socket_name=/tmp/ser_sock

When i call conference, this error appear on screen:

t_get_trans_ident: no transaction found assemble_msg: t_get_trans_ident failed ERROR:tm:t_write_unix: Error in assemble_msg ERROR: t_reply: cannot send a t_reply to a message for which no T-state has been established

Please, Can anyone help me?!!!!??? My operating system is Linux Fedora core 5 ! Thanks