Secondary DT on FXS port

[iptuser]

I've configured a new dial peer for a FXS , incoming via a E1 however when you dial the number from outside you receive secondary DT only on these ports not on any other device. You also see a debug message of
May 29 17:42:59.682: ISDN Se0/1/0:15 **ERROR**: call_progress:
DEV_CONNECTED VOI
CE ERROR: Bearer capability not available(0x3A): b channel 1 call id
0x51A
May 29 17:42:59.682: %ISDN-6-CONNECT: Interface Serial0/1/0:1 is now
connected
Cisco have idenfied a Bug ID CSCse55246 but no real reason or explaination- any idea`s