Hard drive spins down while power adapter is plugged in

[lcampagn]

Binary package hint: laptop-mode-tools

Running kubuntu 9.10 on a lenovo x60 tablet.
I have found on several occasions that my hard drive continues to spin down even after I plug in the power adapter. The problem is not consistent, though, so it has been difficult for me to track.
- I have ENABLE_LAPTOP_MODE=true in /etc/default/acpi-support
- Running 'laptop_mode' says:
    Laptop mode enabled, not active
- But running 'hdparm -C /dev/sda' shows the disk going into suspend mode about once every 30 seconds.
- Running 'hdparm -S0 /dev/sda' seems to have helped.
- Unplugging / replugging the adapter does not help

Possibly related to bug #80331

ProblemType: Bug
Architecture: i386
Date: Tue Apr 6 11:52:35 2010
DistroRelease: Ubuntu 9.10
Package: laptop-mode-tools 1.47-1ubuntu2
PackageArchitecture: all
ProcEnviron:
 LANGUAGE=
 LANG=en_US.UTF-8
 SHELL=/bin/bash
ProcVersionSignature: Ubuntu 2.6.31-21.59-generic
SourcePackage: laptop-mode-tools
Uname: Linux 2.6.31-21-generic i686