AC unplug not detected during suspend

[moose]

steps to reproduce:
-suspend laptop while plugged into AC power
-suspend laptop
-unplug from AC
-turn laptop back on
-power icon and all other battery saving modes remain on AC mode
the battery icon shows charging and the screen does not dim.

What should have happened is the correct power state should have been detected on resume and proper power modes set.

ways to force the change:
-reboot. not ideal
-plug into AC then unplug again. then the state change is detected.

HP G72 ubuntu 11.04 AMD64
This is similar to Bug #670954

ProblemType: Bug
DistroRelease: Ubuntu 11.04
Package: acpi 1.5-2
ProcVersionSignature: Ubuntu 2.6.38-10.46-generic 2.6.38.7
Uname: Linux 2.6.38-10-generic x86_64
NonfreeKernelModules: wl
Architecture: amd64
Date: Thu Aug 4 07:40:05 2011
EcryptfsInUse: Yes
InstallationMedia: Ubuntu 10.10 "Maverick Meerkat" - Release amd64 (20101007)
ProcEnviron:
 LANGUAGE=en_US:en
 PATH=(custom, user)
 LANG=en_US.UTF-8
 SHELL=/bin/bash
SourcePackage: acpi
UpgradeStatus: Upgraded to natty on 2011-04-28 (97 days ago)