Comment 1 for bug 567182

The problem with your disk being marked read-only is probably related to pm-powersave invoking hdparm (via /usr/lib/pm-utils/power.d/95hdparm-apm).

If you boot with the 'nohdparm' option, does this solve the problem?

The acpi-support part of this bug is straightforward - we should not be calling 'invoke-rc.d acpi-support start' in the package postinst, the init script is only meant to be used for setting the initial power management policy at boot time.