asterisk users - Feb 2007 - Call was hangup when LIMIT_WARNING_FILE was playing

Dear All,

I tried to use 'L' option on my dial command.
I set the x to 65000(65 seconds), y to 60000(60 seconds), z to
30000(30 seconds).

The max calltime should be 65 seconds, and it will play "beep.gsm" at
60 seconds left. And repeat the beep at 30 seconds left.

But the call will be hangup by system at 60 seconds left.
In another word, when it plays warning file, the call will be hangup.
The answeredtime is only 5 seconds.

Can anybody give me an idea for it?

*********** extensions.conf ***********************
[default]
exten=> _+[1-9].,1,SetCallerID(22222222)
exten=> _+[1-9].,2,Set(LIMIT_WARNING_FILE=beep)
exten=> _+[1-9].,3,Set(LIMIT_TIMEOUT_FILE=beep)
exten=> _+[1-9].,4,Dial(zap/g1/002${EXTEN:1}|60|L(65000:60000:30000))
exten=> _+[1-9].,105,Hangup


************ Log from CLI
*******************************************************
    -- Seeding '24012100' at 61.217.XXX.XXX:8625 for 60
    -- Accepting AUTHENTICATED call from 61.217.XXX.XXX:
       > requested format = ilbc,
       > requested prefs = (),
       > actual format = ilbc,
       > host prefs = (ilbc),
       > priority = mine
    -- Executing SetCallerID("IAX2/24012100-2", "22222222")
in new stack
    -- Executing Set("IAX2/24012100-2",
"LIMIT_WARNING_FILE=beep") in new stack
    -- Executing Set("IAX2/24012100-2",
"LIMIT_TIMEOUT_FILE=beep") in new stack
    -- Executing Dial("IAX2/24012100-2",
"zap/g1/0028621XXXXXXXX|60|L(65000:60000:30000)") in new stack
    -- Limit Data for this call:
    -- - timelimit     = 65000
    -- - play_warning  = 60000
    -- - play_to_caller= yes
    -- - play_to_callee= no
    -- - warning_freq  = 30000
    -- - start_sound   = UNDEF
    -- - warning_sound = beep
    -- - end_sound     = beep
    -- Requested transfer capability: 0x00 - SPEECH
    -- Called g1/0028621XXXXXXXX
    -- Zap/29-1 is proceeding passing it to IAX2/24012100-2
    -- Zap/29-1 is ringing
    -- Zap/29-1 answered IAX2/24012100-2
    -- Hungup 'Zap/29-1'
  == Spawn extension (default, +8621XXXXXXXX, 4) exited non-zero on
'IAX2/24012100-2'
    -- Hungup 'IAX2/24012100-2'--

Best Regards
Charles