Comment 8 for bug 438355

That next version of Ubuntu is being released tomorrow.

I don't know why you think that the vast majority of Ubuntu users are not going to upgrade. If they're running a standard Ubuntu install, then they will be offered this upgrade automatically; and if they plan to use their netbook for longer than the next year, upgrading is the only way to maintain security support. (If they aren't using a standard Ubuntu install, then an update in the Ubuntu 9.04 repository isn't going to help anyway.)

When on AC power, the default Ubuntu install *always* sets the apm value to 254, which should disable spindown. If you're getting a different value, this isn't originating with Ubuntu. However, there are several bugs in 9.04 regarding the apm settings used while on battery; see /usr/lib/pm-utils/power.d/ for the relevant scripts. You'll also want to delete /etc/pm/sleep.d/99laptop-mode, which was included due to a bug in the laptop-mode-tools package and takes effect even if laptop-mode-tools is disabled.