asterisk users - Jun 2004 - 7960 problem call to 7960

If I call from any cisco device to 7960 asterisk return this message
from 7905G , 7960

Got SIP response 400 "Bad Request" back from 172.16.1.201



but call from asterisk working

7960----->-----7960  Got SIP response 400 "Bad Request" back from 
172.16.1.201
7960----->-----7905G  working
asterisk ------>----- 7960 working
7960 ----->-----asterisk  working
7905G----->-----7960 Got SIP response 400 "Bad Request" back from 
172.16.1.201


I do not think Why

sw 1.01 SIP on 7905G
sw 7.1 SIP on 7960


Thankx all
Help me pleas !!!!!!!!!!