neanche con un altro utente non root funzia (prova:users)

ls -l /usr/bin/
codice:
-rwxr-xr-x  1 root root   46508 19 nov 18:25 yuvcorrect_tune
-rwxr-xr-x  1 root root   47556 19 nov 18:24 yuvdenoise
-rwxr-xr-x  1 root root   15224 19 nov 18:25 yuvfps
-rwxr-xr-x  1 root root   41304 19 nov 18:25 yuvkineco
-rwxr-xr-x  1 root root   16604 19 nov 18:25 yuvmedianfilter
-rwxr-xr-x  1 root root   21504 19 nov 18:25 yuvplay
-rwxr-xr-x  1 root root   53264 19 nov 18:25 yuvscaler
-rwxr-xr-x  1 root root    7296 19 nov 18:25 yuvsplittoppm
-rwxr-xr-x  1 root root    5368 19 nov 18:25 yuvtoppm
-rwxr-xr-x  1 root root   24020 19 nov 18:25 yuvycsnoise
-rwxr-xr-x  1 root root    6084 19 nov 18:25 zeisstopnm
-rwxr-xr-x  1 root root   65004 19 nov 18:24 zip
-rwxr-xr-x  1 root root   27684 19 nov 18:25 zipcloak
-rwxr-xr-x  1 root root    1180 19 nov 18:25 zipgrep
lrwxrwxrwx  1 root root      14 19 nov 18:25 zipinfo -> /usr/bin/unzip
-rwxr-xr-x  1 root root   23328 19 nov 18:25 zipnote
-rwxr-xr-x  1 root root   24672 19 nov 18:25 zipsplit
lrwxrwxrwx  1 root root       6 19 nov 18:25 zsoelim -> soelim
ls -l /var/log/
codice:
drwxr-xr-x  2 root    root        208 10 nov 13:52 apache2
drwxr-xr-x  2 root    root        136 20 ago 18:46 cups
-rw-rw----  1 portage portage  760193 19 nov 16:56 emerge.log
-rw-r--r--  1 root    root     292584 19 nov 20:07 lastlog
drwxr-x---  2 mysql   mysql       144 11 ago 23:14 mysql
drwxr-xr-x  2 root    root         72 13 set  2003 news
-rw-r--r--  1 root    root      27370 16 nov 20:52 scrollkeeper.log
drwxr-xr-x  2 root    root         80  2 lug 15:51 vsftpd
-rw-rw-r--  1 root    utmp    3514752 19 nov 20:07 wtmp
-rw-r--r--  1 root    users     41457 11 ago 07:58 XFree86.0.log
-rw-r--r--  1 root    users     41457 10 ago 19:51 XFree86.0.log.old
-rwxrwxr--  1 root    users     44618 19 nov 20:07 Xorg.0.log
-rwxrwxr--  1 root    users     44758 19 nov 20:02 Xorg.0.log.old
-rwxrwxr--  1 root    users     44683 19 nov 19:33 Xorgold.0.log
-rwxrwxr--  1 root    users     44761 19 nov 18:12 Xorgold.0.log.old
-rwxrwxr--  1 root    users     44157 20 set 19:40 Xorgold.1.log
-rwxrwxr--  1 root    users     43893 21 set 21:11 Xorgold.2.log
-rwxrwxr--  1 root    users     43997 21 set 21:08 Xorgold.2.log.old
anche dando 744 al file in questione non funzia..