Busy Signals After Server Migration

I finally got around from migrating my 5 year old, Asterisk 1.2 box to a new Asterisk 1.8 box. When people attempt an outbound call, the following shows up on the screen and they get a busy signal. It doesn’t happen all of the time and it isn’t reproducible. It just happens.

[Aug 31 11:13:45] ERROR[1775]: chan_dahdi.c:13915 dahdi_pri_error: PRI Span: 1 PTP MDL can't handle error of type F [Aug 31 11:13:45] ERROR[1775]: chan_dahdi.c:13915 dahdi_pri_error: PRI Span: 1 MDL-ERROR (F), SABME in state 7 [Aug 31 11:13:46] ERROR[1775]: chan_dahdi.c:13915 dahdi_pri_error: PRI Span: 1 PTP MDL can't handle error of type F [Aug 31 11:13:46] ERROR[1775]: chan_dahdi.c:13915 dahdi_pri_error: PRI Span: 1 MDL-ERROR (F), SABME in state 7

Stats:
Ubuntu Hardy 64
Asterisk 1.8.5 from the Asterisk repos
Digium Wildcard TE110P

/etc/dahdi/system.conf:

[code]# Span 1: WCT1/0 “Digium Wildcard TE110P T1/E1 Card 0” (MASTER)
span=1,1,0,esf,b8zs

termtype: te

bchan=1-23
dchan=24
echocanceller=oslec,1-23

Span 2: DAHDI_DUMMY/1 “DAHDI_DUMMY/1 (source: HRtimer) 1”

Span 3: WCTDM/0 “Wildcard AEX410 Board 1”

fxsks=25
echocanceller=oslec,25
fxsks=26
echocanceller=oslec,26

channel 27, WCTDM/0/2, no module.

channel 28, WCTDM/0/3, no module.

Global data

loadzone = us
defaultzone = us[/code]

/etc/asterisk/chan_dahdi.conf (Truncated to the card part)

[code]signalling=fxs_ks
context=incoming-local
group=1,2
channel => 25-26

context=incoming-ld
switchtype=dms100
signalling=pri_cpe
group=1,3
channel => 1-23[/code]