In my opinion, Lenovo didn't read the ACPI specification when designing the N100 line of notebooks.
I'm unable to get the backlight class support working on my notebook due to the missing _BQC (Brightness Query Current level) method which is meant to be present in the BIOS.
Lenovo do implement the _BCL (Query List of Brightness Control Levels) and _BCM (Set the Brightness Level) methods, so I just cannot understand why they didn't add the additional three line method to have full support for the ACPI “Output Device” class.
Now, after my partial success in getting a new BIOS from Lenovo to fix the battery reporting (fixes the problems in Windows XP also) I've had no more correspondence from Lenovo. I have also been been sent an email “…IBM/Lenovo provides free software support for the first 30 days after the purchase of the machine… Please note that the software support is chargeable after the first 30 days…“ which I'm guessing is their way of telling me “stop bothering us, go away, we're not interested in fixing anything“. I'm not sure if I should send the notebook back to LENOVO as defective (as it's quite clearly not working with ACPI as advertised) or just send them a bill for my BIOS hacking.
This notebook is fast and Linux support is pretty good, but the BIOS looks like it was rushed and not properly QA'd. At the moment I would probably not recommend Lenovo to somebody that wants Linux compatible hardware, which is a shame considering how good most of the Thinkpads used to be. Perfect Linux support is only a few man-hours of engineer time Lenovo, and I'm sure that would be cost-effective just with one extra bloke choosing Lenovo hardware “because it works with Linux”.