the pg disconnect seems to be a symptom of nsd dying, unrelated to the actual cause. so I'm back to flailing around in the dark.
I ran under gdb for a while but of course it refused to cooperate and crash. Any ideas how to get nsd to dump core when it goes down? (ulimit is set to 1GB so that's not the problem. and other programs are happy to dump core on segfault... just not nsd.)