lo interface not coming up

[Derek Broughton]

What could cause "lo" to fail to initialize?

Frequently, on boot, the interface doesn't come up - or rather "ifup lo"
says it's already configured but "ifconfig lo" shows nothing, so I have to
do "ifdown lo; ifup lo".

/etc/network/interfaces as "auto lo" and "iface lo inet loopback"

/etc/rcS.d/S40networking appropriately points to the init script from the
netbase package (and this is presumably working, anyway, as "ifup lo" must
be executed - it just doesn't finish.

This proceeds to break all sorts of other things like my MTA, browser proxy,
and just about anything in KDE.
-- 
derek