I registrar kamailio ofen can registrar .but at other wifi some time i use the csipsimple registrar kamailio get request time out . when i look up the log I have found

ERROR: registrar [save.c:692]: update_contacts(): invalid cseq for aor <1008>

I search on google but can`t find a good answer. some one tell me it's not a same callid and low cseq .

what would i do for this error ?