High power consumption and general overheat in ubuntu 11.04.

Hi. First of all I am not sure this is the right way to report such a bug. Secondly I am a rather inexperienced user and have no idea on how to fix anything or even how to send more detailed specifications. I have an Acer Aspire 5741G, Intel Core i3 330M 2.13 GHZ with an ATI Radeon HD 5470 512 MB, 4GB RAM DDR3 (1066MHz) and a Toshiba 320 GB HDD.
I have recently installed ubuntu 11.04 amd64, and since then I have noticed that my battery "empties" in an hour or even less, while with maverick, I was able to use it more than 3 and a half hours. I could even watch a full 2-hour film only with battery supply (which I had done several times since at home we suffer from power blackouts).
Also it suffers from general overheat. The whole notebook (CPU, GPU, RAM, HDD) burns, so I can't exceed the 2 hours of continuous usage.
I don't do anything extreme or use high consumption applications; a little firefox, pidgin, openoffice and pidgin. Last Sunday, after two hours of continuous usage (a few tabs on firefox, chat on pidgin and banshee playing), I had some freezes. When I opened gnome-system-monitor I saw that RAM usage was 3,5 GB and Swap 2,1 GB. I also noticed that notebook overheats even if I don't use any programme.
I repeat that I didn't have anything similar in Maverick. I am an ubuntu user since 2008 and 8.04 Hardy Heron, and I have never seen anything similar.
I am not sure whether it is a X.org bug or a kernel (2.6.38) bug.