I HAVE THE SOFTWARE 21.2011.38.1 ON MY N900.when i install from CSSU the software open a window of Xterm and he do the operation . after that he said me that is an error i don't remember where and he talk me to press a key to get out . ok after that i install the update . after that the orientation LANDSCAPE - Horizondat - vertical doesnt work . same thing in the applications ... i dont know what to do. i will REINSTALL ALL THE MAEMO and i will not install ever CSSU .i cant take a software if is not working.better get him out.thanks

Please calm down. Youd might want to read the wiki before installing cssu, and, do you have the right repos enabled?

i presume you have followed another forum about installing cssu, that's why things get messed sometimes
the wiki shall be your friend

./sifo

i follow the video on youtube posted by maemo.org.
i guess is this one
https://www.youtube.com/watch?v=uMHxo1ALXNE
but i cant use the cssu.i make a backup but the software is there again.
how can i uninstall cssu and install it again but with the right GUIDE. Thanks for the answers.

Well that was "the right guide"
optional :
i have installed cssu by terminal more than 3 times you can follow this if you want ( AT YOUR OWN RISK !!!! )

1- make sure you are connected to the Internet
2- add the cssu repository to /etc/apt/sources.list.d/hildonaplication manager.list
-if you want testing flavor add :
deb http://repository.maemo.org/community-testing/ fremantle free non-free
-if you want the stable add :
deb http://repository.maemo.org/community/ fremantle free non-free
4- there is no number four
5- go to x terminal and gain root
6- it should update without errors
7- 8-then wait until it finishes and you need to confirm a notification or 2, after it is done reboot !
9- congratz you have cssu now !
10- remember at your own risk
good luck

./sifo

well if this is so dangerous ... better keep the phone without Cssu. i like so much the phone in vertical mode but if this have a risk i prefer to keep it in horizontal mode and install applications with vertical mode enabled.thanks so much for the help to all.

It is not like that, but im saying "at your own risk" because if something goes wrong you can't say that happened because of me
good luck

./sifo

no no don't thinking like that. i just saying if something getting wrong for example the phone get dead and not getting on , i prefer to keep it in this mode (horizontal). i have allready the backup and another guide to flashing the phone so i don't worry about it. i don't want to put the phone in skin of dead . one time i was risked to lose him . i don't want a second time to lose it.thanks a lot sifo

it is up to you
here in TMO we are all using cssu afaik

Well, maybe a few of us aren't yet using it.