su spot not working

[skhare]

Got PuupyLinux 2.17 but somehow I am not able to install a package which requires non root user.When I do su spot it gives an error /bin/sh ..permission denied/

I changed group and owner permision in /usr/bin and /usr/local/bin and /usr/sbin to root. But still without luck. What am I doing wrong. Also I just wanted to check whether it is alright to set every file owner and group to root/

Thanks
Shash