The Emachines EM250 netbook "rebadged acer aspire" works perfect on a hard disk install of bt4. However, it throws out an acer-wmi device not found on startup.. This means a couple of the function keys will not work. Those are the ones which control the acpi functions.
After hacking my install to pieces for a few days with no luck(pm-utils, powermanager, kpowersave), I decided to give up on trying to fix it. Until recently when I was messing around with kde kdm I found that kdm's gui shutdown menu had suspend and hibernate added to it so I gave hibernate a shot and voila! gives 1 or 2 warnings about irq stat and some other exception but it actually does hibernate and resume on power on.
I would of been happy with just a command line hibernate..but there you have it right inside kde!
open terminal and type: sudo apt-get install kdm
Final note: if you want an even quicker resume with no error msgs just hit suspend instead. No need to blacklist acer-wmi.