asterisk users - Aug 2005 - chan_sip.c: stale nonce received

I have this error
Aug 27 13:31:46 NOTICE[2863] chan_sip.c: stale nonce received from
'656720189<sip:6562720189@69.12.30.109;user=phone>'
generated for two equipment hardwired in asterisk. Some friend can help me?

Thank's
Jo?o Carlos Moura