It appears to be a problem when registering to one of my trunks. The very strange thing is the everything will be working perfectly and then all of a sudden this happens, i.e. trunks regged, calls completing, etc. This is a very lightly loaded server.
freeswitch@internal> 2010-03-14 23:12:15.199983 [NOTICE] sofia_reg.c:336 Registering bandtel
2010-03-14 23:12:15.223977 [DEBUG] sofia_reg.c:1478 Changing expire time to 475 by request of proxy
sip:66.237.65.672010-03-14 23:20:05.429613 [NOTICE] sofia_reg.c:336 Registering bandtel
2010-03-14 23:20:08.285756 [ERR] sofia_reg.c:1490 bandtel Registration Failed with status Operation has no matching challenge [904]. failure #1
2010-03-14 23:20:10.043933 [WARNING] sofia_reg.c:381 bandtel Failed Registration, setting retry to 60 seconds.
2010-03-14 23:21:16.332797 [NOTICE] sofia_reg.c:336 Registering bandtel
2010-03-14 23:21:52.528409 [WARNING] sofia_reg.c:381 bandtel Failed Registration, setting retry to 60 seconds.
2010-03-14 23:22:56.945511 [NOTICE] sofia_reg.c:336 Registering bandtel
2010-03-14 23:23:33.083177 [WARNING] sofia_reg.c:381 bandtel Failed Registration, setting retry to 60 seconds.
2010-03-14 23:24:37.398155 [NOTICE] sofia_reg.c:336 Registering bandtel
2010-03-14 23:25:13.631825 [WARNING] sofia_reg.c:381 bandtel Failed Registration, setting retry to 60 seconds.
2010-03-14 23:26:17.978767 [NOTICE] sofia_reg.c:336 Registering bandtel
2010-03-14 23:26:54.172425 [WARNING] sofia_reg.c:381 bandtel Failed Registration, setting retry to 60 seconds.
2010-03-14 23:27:58.579354 [NOTICE] sofia_reg.c:336 Registering bandtel
2010-03-14 23:28:34.605017 [WARNING] sofia_reg.c:381 bandtel Failed Registration, setting retry to 60 seconds.