Asterisk 1.4.36 running on CentOS 5.6 (64 bit)
Everything works except one deal killer: it is not hearing DTMF tones from either internal extensions or from callers calling in on SIP trunks. DTMF coming in via IAX2 works just fine. I have been beating my brains out since this is just one server of dozens of more or less identical servers that all work flawlessly.
I have tried tinkering with SIP settings [relaxdtmf=yes] but nothing makes any difference so far.