Major network problems with OpenBSD 2.3

[Gert-Jan Vons <vons_(_at_)_club-internet_(_dot_)_fr>]

Hello all,

I'm having a major problem with network access under OpenBSD 2.3/i386.
Since I've installed this version, I'm lucky when the system stays
in the air for more than five minutes :-(

When I'm accessing the network using NFS for example, an 'ls' will cause
the system to reboot, I don't even get into the kernel debugger.

I can reliably reproduce this problem with ftp:

1) an ftp put of a big file to another machine works fine.

2) get-ting the same file back to OpenBSD 2.3 immediately reboots the
   OpenBSD system.

Suspecting the driver for my network card (ISA-based NE2000 clone, sold as
SN2000, "Novell Approved"), I also tried both the latest if_ed.c from
www.openbsd.org as well as the if_ed.c from OpenBSD 2.2, and the problem
exists with both versions.

Running the same test with OpenBSD 2.2 shows no problem at all, 2.2 still
runs fine on this machine (as does FreeBSD).

Does someone know what might cause this, or how I can debug this ?

        Gert-Jan