I just created a partition by gparted as Ext3 by I can change the permissions for the partion .......I can´t copy or create any folder in the partition because of the permission ... I think there are some issues about mounting the partition because I can create files and folders in my old NTFS partitions ... I think I have to change the settings in the system setting --> disk & filesystem but I dont know what to change exactly ... thank you so much for your help
here is a screenshot of disk and filesystem window
http://www.fileden.com/files/2008/2/10/1750875/1.png

did you format the partition ?

Have you changed /etc/fstab as root to reflect the changes in that partition ? If they aren't correct, not only will you be unable to do anything with the partition on boot, but the mount command won't work correctly either, as mount pulls info from /etc/fstab. If you post your current fstab, what partition you changed and what you changed it to, we can point you in the right direction.

David

mehdi@ubuntu:/etc$ cat fstab
# /etc/fstab: static file system information.
#
# <file system> <mount point> <type> <options> <dump> <pass>
proc /proc proc defaults 0 0
# /dev/sda1
UUID=3e0a776a-ea9e-49cd-bb76-06ad5103c9db / ext3 nouser,defaults,errors=remount-ro,atime,auto,rw,dev,exec,suid 0 1
# /dev/sda5
UUID=E250156A501546A7 /media/sda5 ntfs defaults,umask=007,uid=0,gid=46,auto,rw,nouser 0 1
# /dev/sda6
UUID=6C30FD3230FD03BC /media/sda6 ntfs defaults,umask=007,uid=0,gid=46,auto,rw,nouser 0 1
# /dev/sda7
UUID=C0CCE8CDCCE8BEB2 /media/sda7 ntfs defaults,umask=007,uid=0,gid=46,auto,rw,nouser 0 1
# /dev/sda8
UUID=D89CF8789CF8528C /media/sda8 ntfs defaults,umask=007,uid=0,gid=46,auto,rw,nouser 0 1
# /dev/sda9
UUID=776a6265-eb94-45c7-a05e-477ea678bca1 none swap sw 0 0
/dev/scd0 /media/cdrom0 udf,iso9660 user,atime,noauto,rw,dev,exec,suid 0 0
/dev/fd0 /media/floppy0 auto user,atime,noauto,rw,dev,exec,suid 0 0
LABEL=Linux\040Documents /media/sda3 auto nouser,atime,noauto,rw,nodev,noexec,nosuid 0 0
/dev/sda3 /media/sda3 ext3 nouser,atime,auto,rw,dev,exec,suid 0 0
mehdi@ubuntu:/etc$