"PRI Error on span 2: We think we're the CPE, but they think they're the CPE too" Problem.

I've found this massage on asterisk log (/var/log/asterisk/full)

PRI Error on span 2: We think we're the CPE, but they think they're the CPE too

This problem is solved by edit /etc/asterisk/dahdi-channels.conf

change

switchtype = national
signalling = pri_net

Note.
Solution from
http://community.spiceworks.com/topic/487804-pri-cards-where-is-the-problem
and
http://forums.digium.com/viewtopic.php?f=1&t=5937&start=0