smpp connection spolit after a while

hi all!
    My kannel version: 1.2.1
    I'm connecting to smsc with smpp.


    I'm getting this error often,
2003-10-01 15:51:01 [6] ERROR: error connecting to server `xx.xx.xx.xx' at port `5016'
2003-10-01 15:51:01 [6] ERROR: SMPP[SMPP_ABCD]: Couldn't connect to server.
2003-10-01 15:51:01 [6] ERROR: SMPP[SMPP_ABCD]: Couldn't connect to SMS center (retrying in 10 seconds).
2003-10-01 15:51:13 [6] ERROR: SMPP[SMPP_ABCD]: SMSC rejected login to transmit, code 0x0000000d.
2003-10-01 15:51:13 [6] ERROR: SMPP[SMPP_ABCD]: I/O error or other error. Re-connecting.

    But once connected this stops and working fine. Whenever this happen I can't connect to the smsc immediatedly by restarting the kannel. What are the reasons for this to happen ? Is it a bug in the code ? What remedies/precautions could I take to avoid this ?



denzel.