I've installed the sony erricsson se-nse megapack and it worked fine!
Can anyone tell me how to use book manager 1.2??? or what purpose it has??? or how to customize it??? I've searched a little bit for this but I wasn't able to found any topic special made for it.
Any info appreciated !

you push your activity button. and it pops up. it basically lets you run a lot of stuff at once, a process explorer.

that's right. you can minimize and maximize any process in your phone using bookmanager.

Can someone plz tell me how to add heap shifts to bookmanager in order to stabalise it and reduce the chances of my phone crashing.
I have a W810i and whenever my phone tells me there isn't enough space for a file and asks me to delete something to make space, when i click no it crashes. Sometimes when i click yes and press the arrow button it also crahes. I am afraid of minimising too many things using bookmanager and would very much appreciate it if someone can assist me.

here's my advice for you... remove bookmanager.