I have a Mac IIcx (several actually) with a clean NetBSD install (tried several times over), which boots fine, then boots again fine after RCCONFIGURED=YES, but dies after a few hours. What's the problem?

Here are some specifics:

Mac IIcx 8/80 (same results on 20/250 and another IIcx)
NetBSD 1.4.2
Installed base, kern and etc
16 MB scratch, 61MB Root & Usr, 5MB MacOS
Followed instructions at:
  http://users.erols.com/ewinkler/installguide/installguide.html

Runs fine. I can install and configure etc. But it dies within 24 hours, sometimes with no keyboard and network response (ie it's frozen), sometimes with a long debug message array. The one I'm looking at now says:

Kernel FPU trap
trap type 16, code = 0x0, v = 0x0
kernel program counter = 0x321000c
kernel: type 16 trap
pid = 144, pc = 0321000C, ps = 2704, sfc = 1, dfc = 1
Registers: <two long hex lines>
Kernel stack (006AED44): <16 long hex lines>
panic: trap
Stopped in inetd at     _Debugger+0x6:  unlk   a6
db>

The last time I paid attention to the debug output, the PID also matched inetd. So is there some known problem with inetd? How can I fix it?

In contrast, I installed ewinkler's prebuilt firewall gzip archive on the same IIcx Macs (with 250MB hard disk) and it runs without error, but I want to use less disk space and build on the basics rather than stripping off what I don't need.

Any help very welcome, especially yesterday ;-)

Thanks,
Tom
T&B