To get back to the original poster's possible situation, i've seen this with my first IP phone, which was a cisco 7912 (SIP image). With that phone, asterisk sometimes gave me this same error. I'm quite sure i've asked the very same question here back then (probably i was a bit more specific :). Since it is related to only this type of phone, i've gone to different ip phone products.
regards adam -- _____________________________________________________________________ -- Bandwidth and Colocation Provided by http://www.api-digital.com -- asterisk-users mailing list To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users