Hi Robert!
Just a thought but the buffering may be a bit off on this. It seems the commands from ircservices are not being properly interpreted somewhere. The last built I had that did work correctly. That one had a version string of ngircd-17.1~55-g5417a72 being it was from the git rep when I did it. The one I did just now was done today and I got all those errors above. The debug build doesn't provide any additional information otherwise I would provide that as well. If there is anything you can advise then I'm open for it.
Most probably this is caused by commit 15775e679, „Commands received from other servers must have prefixes“ (http://arthur.barton.de/cgi-bin/gitweb.cgi?p=ngircd.git;a=commitdiff;h=15775e679). Can you try to revert it?
I try to reproduce it and will fix it in our master branch (should be quite simple), it definitely is a bug.
Can you try this (more or less) untested patch? It should solve the problem:
http://barton.de/stuff/ngIRCd/patches/no-prefixes-rfc1459.patch
Regards Alex