His problem is here:
See this log entry:
[Oct 21 00:46:18] WARNING[2817]: app_rpt.c:21237 rpt_exec: Cannot find specified system node 1998

When he connects to his node from DVSM, the section in extensions:

[phone-iaxrpt]    ;;; Stanza is the context from iax.conf
exten => 519980,1,Answer
exten => 519980,n,Playback,rpt/node
exten => 519980,n,Playback,digits/1
exten => 519980,n,Playback,digits/9
exten => 519980,n,Playback,digits/9
exten => 519980,n,Playback,digits/8
exten => 519980,n,Set(CALLERID(num)=0)
exten => 519980,n,Rpt,1998|P|${CALLERID(name)} ;;; The "CallerID" from IAXRpt

Which is HARD Coded to connect to node 1998. This is the the default HAMVIOP stanza. Rather then using a variable like oh say something like NODE" is it is here:

[globals]
NODE = 1999

[iax-client]
exten => ${NODE},1,Ringing
exten => ${NODE},n,Wait(3)
exten => ${NODE},n,Answer
exten => ${NODE},n,Set(RPT_NODENUM=${CALLERID(number)})
exten => ${NODE},n,Playback(connected)
exten => ${NODE},n,Set(CALLERID(num)=0)
exten => ${NODE},n,Rpt,${NODE}|P|${CALLERID(name)}
exten => ${NODE},n,Hangup
exten => ${NODE},n(hangit),Answer
exten => ${NODE},n(hangit),Wait(1)
exten => ${NODE},n(hangit),Hangup

This way, all you need to do is set the value NODE in the top of the file file and you are done. Yes, there are other differences but the concept is the same.
At the end of the day, the HAMVOIP document explains how to configure the node for DVSM. Now, if they would just update the doc file and method...