Ubuntu bad energy management over a Toshiba netbook

Using (L)Ubuntu 11.10 Oneiric Ocelot in a Toshiba Netbook, model NB500-108

I'm experiencing bad power and energy management:
- The battery dries too fast, It lasts 3 or 4 hours less in comparison to the pre-installed Win 7 Starter;
- A little overheating (once again, in comparison to the pre-installed Win 7 Starter) with temperatures easily reaching 60ºC;
- Erroneous informations about the battery like in these two examples:
1. The battery reaches 21% of its capacity and Ubuntu says it will only take 2 minutes untill its tottaly charged. Here's a screenshot: http://imageshare.web.id/images/8xdx5u6srjbu4aszuz.png
2. After unpluggin the AC power cable I get a notification saying the estimated time left are 3 minutes despite the battery is 100% charged: http://imageshare.web.id/images/8xehv1duwb92fuo9kpp2.png
Both messages are wrong, of course, but they have no further consequences.

I've already tried CPU scalling and frequency utils, jupiter app, adjusted the power management in many ways, etc. all without significantly success.

Netbook specs:
http://uk.computers.toshiba-europe.com/innovation/jsp/SUPPORTSECTION/discontinuedProductPage.do?service=UK&toshibaShop=false&com.broadvision.session.new=Yes&PRODUCT_ID=1098378