APM: will not sleep with AC plugged in?

[Brandon Kuczenski <brandon@301south.net>]

Recent upgrade to Debian Sarge on a Thinkpad T23, with kernel 2.6.8,
home-brewed.  I had initially intended to use ACPI, but I couldn't get it
working and since APM works flawlessly on this machine, I thought I would
stick with it.

But the laptop will not sleep with the AC plugged in.  Now I've googled
and I've seen that this is something of a 'feature' rather than a 'bug.'
In my /etc/apm/apmd_proxy file there is the block of code:

#SUSPEND_ON_AC=false
#[ -r /etc/apm/apmd_proxy.conf ] && . /etc/apm/apmd_proxy.conf
#
#if [ "${SUSPEND_ON_AC}" = "false" -a "${2}" = "system" ] \
#	&& on_ac_power >/dev/null; then
#    # Reject system suspends and standbys if we are on AC power
#    exit 1  # Reject (NOTE kernel support must be enabled)
#fi

but it's COMMENTED OUT!  So I think the suspension is being stopped
somewhere downstream of apmd_proxy.  I checked BIOS settings but couldn't
find anything pertaining to this.  The 'old' system was running Redhat 9
and suspended on AC power just fine.

So where should I look?

Thanks,
Brandon