maacruz
I am very sorry about all worries I've brought to you, the battery issue solved!

Actually auouymous's advanced-systemui was leaking my battery very much, once I deleted it n810 became as usable as it was before installation!
The thing is that I installed both Diablo turbo and advanced-systemui in a same day so i really didn't know what eats the energy.

Today I had 6 lessons (80 minutes each one), spend it watching Simpsons (mplayer), playing wormux with table-mate and riding the civil and housing code (I study law) plus 30 minutes BT and Opera browsing and chat plus 2 hours of music (mplayer) and I still got 24% of battery. As good as it was! And I think I really found my device works slightly faster!