Asterisk Crashes When Calling Queue Application

Hi…

First of all I put my system info.
I have CentOS 5.3(Final)
I have asterisk version Asterisk 1.6.0.22.
I have trixbox version 2.8.0.3

I have configured a queue with a static member as member=Local/503@from-internal/n,0. When I dial extension it puts me in the queue and i hear MOH but its not start ringing to member extension. in this case when I give command on CLI.
CLI>queue show 595

it gives output

queue show 595
595 has 1 calls (max unlimited) in ‘rrmemory’ strategy (0s holdtime), W:0, C:0, A:1, SL:0.0% within 0s
Members:
Local/503@from-internal/n (Not in use) has taken no calls yet with total talktime 0s
Callers:
1. SIP/UK-00000001 (wait: 0:04, prio: 0)

Also when I put sip extension as member in the queue member=SIP/503 and dialed from sip extension asterisk crashes with the message.

Segmentation fault (core dumped).
I don’t get understand what is the problem and where is it. Please help me.

Thanks.