[bglug] problema permessi

[capyf]

Ciao a tutti,sono Davide e chiedo info per la mia Ubuntu 11.04 in quanto
per un comando errato (che non sò quando)mi impedisce comandi in
root :gestore pacchetti e altro con risposta:sudo: must be setuid root.

Con :ls -la /usr/bin/sudo
---x--x--x 2 davide root 144508 2011-05-30 07:51 /usr/bin/sudo 
(/usr/bin/sudo) in una casella in Rosso....? 

Posto anche :
davide@davide-GA-7VA:~$ ls -la /

totale 100
drwxr-xr-x  23 root   root  4096 2011-08-25 06:21 .
drwxr-xr-x  23 root   root  4096 2011-08-25 06:21 ..
drwxr-xr-x   2 root   root  4096 2011-07-29 10:55 bin
drwxr-xr-x   3 root   root  4096 2011-08-19 15:24 boot
drwxr-xr-x   2 root   root  4096 2011-06-24 17:41 cdrom
drwxr-xr-x  19 root   root  4800 2011-08-26 17:33 dev
drwxr-xr-x 147 root   root 12288 2011-08-26 17:33 etc
drwxr-xr-x   5 root   root  4096 2011-06-26 04:53 home
lrwxrwxrwx   1 root   root    33 2011-08-19 15:24 initrd.img ->
boot/initrd.img-2.6.38-11-generic
lrwxrwxrwx   1 root   root    33 2011-08-19 15:20 initrd.img.old ->
boot/initrd.img-2.6.38-11-generic
drwxr-xr-x  21 root   root  4096 2011-08-17 09:10 lib
drwx------   2 root   root 16384 2011-06-24 17:31 lost+found
drwxr-xr-x   3 root   root  4096 2011-08-26 08:15 media
drwxr-xr-x   2 root   root  4096 2011-02-24 13:06 mnt
drwxr-xr-x   2 root   root  4096 2011-03-29 18:13 opt
dr-xr-xr-x 177 root   root     0 2011-08-26 19:32 proc
drwx------  19 root   root  4096 2011-08-19 14:27 root
drwxr-xr-x   2 root   root  4096 2011-06-30 08:32 .rpmdb
drwxr-xr-x   2 root   root  4096 2011-08-25 06:28 sbin
drwxr-xr-x   2 root   root  4096 2011-03-21 09:26 selinux
drwxr-xr-x   2 root   root  4096 2011-03-29 18:13 srv
drwxr-xr-x  12 root   root     0 2011-08-26 19:32 sys
drwxrwxrwt  17 root   root  4096 2011-08-26 17:39 tmp
drwsrwsr-t  14 davide root  4096 2011-08-11 15:00 usr
drwxr-xr-x  15 root   root  4096 2011-03-29 18:29 var
lrwxrwxrwx   1 root   root    30 2011-08-19 15:24 vmlinuz ->
boot/vmlinuz-2.6.38-11-generic
lrwxrwxrwx   1 root   root    30 2011-08-19 15:20 vmlinuz.old ->
boot/vmlinuz-2.6.38-11-generic

Grazie per un aiuto

Davide