vgetty: runs from console but not from inittab

Cluebat requested re vgetty: console vs init problem(s).
I'm likely missing something very obvious and very basic
but I've been staring at it for quite a while and haven't
spotted it yet. Thanks in advance for any help.
Suggestions also welcome if this is not the best forum
for this.

Right now, on this system[2],

either of the following work[1] from a console

$ /usr/sbin/vgetty ttyS1
# /usr/sbin/vgetty ttyS1

the following does not work from /etc/inittab[4]
(after #init q or reboot)

S1:345:respawn:/usr/sbin/vgetty ttyS1

[1] by "work", I mean that modem detection succeeds,
and /var/log/mgetty/ttyS1.log[3] is created and incoming
calls are detected and the modem will go off-hook. The
process table in KDE System Guard shows an entry for
vgetty. None of these things happen using the line in
inittab. There are obviously other problems also as
shown in the logs, but I think it might be best to solve
my console vs inittab problem first.

[2]Debian etch
# uname -a
Linux omega 2.6.17-2-vserver-k7 #1 SMP Wed Sep 13 19:32:15 UTC 2006 i686 GNU/Linux

[3]snippet(s):
11/25 19:46:02 yS1 vgetty: experimental test release 0.9.32 / with duplex patch
11/25 19:46:02 yS1 mgetty: interim release 1.1.35-Feb22
11/25 19:46:02 yS1 WARNING: parent process not init(pid=1), but pid=5078 (bash)
11/25 19:46:02 yS1 reading generic configuration from config file /etc/mgetty/voice.conf
11/25 19:46:02 yS1 reading program vgetty configuration from config file /etc/mgetty/voice.conf
[...]
11/25 19:46:04 yS1 send: AT[0d]
11/25 19:46:04 yS1 waiting for ``OK''
11/25 19:46:04 yS1 got: [0d]
11/25 19:46:04 yS1 CND: OK[0a][0d][0a]OK ** found **
11/25 19:46:04 yS1 mdm_send: 'ATI'
11/25 19:46:04 yS1 got:[0d][0a][0d][0a]56000[0d]
11/25 19:46:04 yS1 mdm_gis: string 1: '56000'
11/25 19:46:04 yS1 got:[0a][0d][0a]OK[0d]
11/25 19:46:04 yS1 mdm_identify: string '56000'
11/25 19:46:04 yS1 Generic Rockwell modem (56000)
11/25 19:46:04 yS1 mdm_send: 'ATI3'
11/25 19:46:04 yS1 got:[0a][0d][0a]ACF3_V1.088-V92_P21_FSH[0d]
11/25 19:46:04 yS1 mdm_gis: string 1: 'ACF3_V1.088-V92_P21_FSH'
11/25 19:46:04 yS1 got:[0a][0d][0a]OK[0d]
11/25 19:46:04 yS1 mdm_send: 'ATI4'
11/25 19:46:04 yS1 got:[0a][0d][0a]AOpen FM56-EXV Modem[0d]
[...]
1/25 19:46:06 yS1 vgetty: entering voice mode
11/25 19:46:06 yS1 vgetty: Installing signal handlers
11/25 19:46:06 yS1 voice command: 'AT#CLS?' -> ''
11/25 19:46:06 yS1 vgetty: AT#CLS?
11/25 19:46:06 yS1 Rockwell: ERROR
11/25 19:46:06 yS1 voice command: '' -> 'OK'
11/25 19:46:06 yS1 Rockwell:
11/25 19:46:17 yS1 vgetty: timeout while reading character from voice modem
11/25 19:46:17 yS1 vgetty: queued event RESET_WATCHDOG at position 0000
11/25 19:46:17 yS1 initializing ROCKWELL voice modem
11/25 19:46:17 yS1 voice command: 'AT#VSP=70' -> 'OK'
11/25 19:46:17 yS1 vgetty: AT#VSP=70
11/25 19:46:17 yS1 vgetty: unqueued event RESET_WATCHDOG at position 0000
11/25 19:46:17 yS1 vgetty: voice_handle_event got event RESET_WATCHDOG with data
11/25 19:46:17 yS1 Rockwell: ERROR
11/25 19:46:17 yS1 vgetty: Modem returned ERROR
[...]
11/25 19:46:18 yS1 running post_init_chat
11/25 19:46:18 yS1 send: AT+VCID=1[0d]
11/25 19:46:18 yS1 waiting for ``OK''
11/25 19:46:18 yS1 got: [0d]
[...]
11/26 13:51:00 yS1 select returned 1
11/26 13:51:00 yS1 checking lockfiles, locking the line
11/26 13:51:00 yS1 makelock(ttyS1) called
11/26 13:51:00 yS1 do_makelock: lock='/var/lock/LCK..ttyS1'
11/26 13:51:00 yS1 lock made
11/26 13:51:00 yS1 vgetty: number of rings (99) was set directly
11/26 13:51:00 yS1 wfr: waiting for ``RING''
11/26 13:51:00 yS1 got: [0a][0d][0a]RING[0d]
11/26 13:51:00 yS1 CND: RING
11/26 13:51:00 yS1 wfr: rc=0, drn=0
[...]
11/26 13:51:21 ##### phone stopped ringing (rings=3, dev=ttyS1, pid=5103, caller='none')

[4]complete /etc/inittab:
# /etc/inittab: init(8) configuration.
# $Id: inittab,v 1.91 2002/01/25 13:35:21 miquels Exp $

# The default runlevel.
id:2:initdefault:

# Boot-time system configuration/initialization script.
# This is run first except when booting in emergency (-b) mode.
si::sysinit:/etc/init.d/rcS

# What to do in single-user mode.
~~:S:wait:/sbin/sulogin

# /etc/init.d executes the S and K scripts upon change
# of runlevel.
#
# Runlevel 0 is halt.
# Runlevel 1 is single-user.
# Runlevels 2-5 are multi-user.
# Runlevel 6 is reboot.

l0:0:wait:/etc/init.d/rc 0
l1:1:wait:/etc/init.d/rc 1
l2:2:wait:/etc/init.d/rc 2
l3:3:wait:/etc/init.d/rc 3
l4:4:wait:/etc/init.d/rc 4
l5:5:wait:/etc/init.d/rc 5
l6:6:wait:/etc/init.d/rc 6
# Normally not reached, but fallthrough in case of emergency.
z6:6:respawn:/sbin/sulogin

# What to do when CTRL-ALT-DEL is pressed.
ca:12345:ctrlaltdel:/sbin/shutdown -t1 -a -r now

# Action on special keypress (ALT-UpArrow).
#kb::kbrequest:/bin/echo "Keyboard Request--edit /etc/inittab to let this work."

# What to do when the power fails/returns.
pf::powerwait:/etc/init.d/powerfail start
pn::powerfailnow:/etc/init.d/powerfail now
po::powerokwait:/etc/init.d/powerfail stop

# /sbin/getty invocations for the runlevels.
#
# The "id" field MUST be the same as the last
# characters of the device (after "tty").
#
# Format:
# :::
#
# Note that on most Debian systems tty7 is used by the X Window System,
# so if you want to add more getty's go ahead but skip tty7 if you run X.
#
1:2345:respawn:/sbin/getty 38400 tty1
2:23:respawn:/sbin/getty 38400 tty2
3:23:respawn:/sbin/getty 38400 tty3
4:23:respawn:/sbin/getty 38400 tty4
5:23:respawn:/sbin/getty 38400 tty5
6:23:respawn:/sbin/getty 38400 tty6

# Example how to put a getty on a serial line (for a terminal)
#
#T0:23:respawn:/sbin/getty -L ttyS0 9600 vt100
#T1:23:respawn:/sbin/getty -L ttyS1 9600 vt100

# Example how to put a getty on a modem line.
#
#T3:23:respawn:/sbin/mgetty -x0 -s 57600 ttyS3

S1:345:respawn:/usr/sbin/vgetty ttyS1