With NetBSD 1.4.1 the following sequence of commands crashes my PC
(the commands are part of my ip-up and ip-down scripts, -E in ip-up and
-D in ip-down):
    /sbin/ipf -E
    /sbin/ipf -D
    /sbin/ipf -E
    /sbin/ipf -D

I get:
    pfil_list_remove:  no function on list
    panic: pfil_list_remove
    Stopped in ipf at    _Debugger+0x4:  leave

Sometimes, before that I get:
    Data modified on freelist: word 0 of object 0xf0500a90 size 4
    previous type ifaddr (0xf05008b0 != 0xdeadbeef).

'sysctl -a | grep forward' says:
    sysctl: machdep.diskinfo: unknown structure returned
    net.inet.ip.forwarding = 1
(BTW what does the first line mean?)

The ipf.conf file is empty:
    -rw-r--r--  1 root  wheel  0 Oct 24 00:23 /etc/ipf.conf

I don't recall that this happened with 1.3.2 or 1.4; now I can't connect
to my provider twice without rebooting.

Any help is appreciated,
Federico Lupi