Problems with resoluction

First sorry for my english ..i wil try to be as close as possible with my problem. I install Kubuntu Gutsy Gibon 7.10 on my pc ..and first time run well with a good configuration ...but when i go off and restart the computar again ..it opens with a new resoluction. My graphics card is nvidia xfx gforce 6200 . I have allready configure the xorg.conf files and also install the drivers for my card but still have problems when i login ...and now i have on the login menu to change allways the xorg.conf to one backup. I allready do this:

sudo apt-cache search nvidia
sudo apt-get install nvidia-glx
sudo apt-get install nvidia-kernel-source
sudo apt-get install xserver-xorg-driver-nv

But still with the same ..when login every thing goes black and i have to change (via console) the xorg.conf file to a backup.
Well what i want is for someone to help me from the beginning ..maybe i have to delete some files and install the correct drives ...I just dont Know....Please someone help-me step by step from the begining.
The resoluction that i want is : 1024 *728
 Many thanks for all .