asterisk users - Aug 2009 - No translator path exists for channel type dahdi

Hi,
I have a 4 port analog cards with asterisk 1.4.26.1 (centos5.3)
installed.  After I dial an outgoing call, it returns error and call
drop as below.  Anyone can tell me what the problem is.  ango

    -- Executing [8200 at internal:20] Dial("SIP/601-09425ab8",
"dahdi/g0/8200|50|T") in new stack
[Aug 25 16:43:40] WARNING[2505]: channel.c:3372 ast_request: No
translator path exists for channel type dahdi (native 76) to 256
[Aug 25 16:43:40] WARNING[2505]: app_dial.c:1275 dial_exec_full:
Unable to create channel of type 'dahdi' (cause 58 - Bearer capability
not available)
  == Everyone is busy/congested at this time (1:0/0/1)
    -- Executing [8200 at internal:21] Hangup("SIP/601-09425ab8",
"") in new stack
  == Spawn extension (internal, 8200, 21) exited non-zero on
'SIP/601-09425ab8'