SEVERE Problems in 2.5.12 at uid0 access

[system_lists@nullzone.org]

server01:/ # cd /var/log

server01:/var/log# ls -laF
<snip>
drwxr-s---    2 mail     adm           104 Mar 12 23:29 exim/
<snip>

server01:/var/log# ls -laF exim
ls: exim/.: Permission denied
ls: exim/..: Permission denied
ls: exim/rejectlog: Permission denied
ls: exim/mainlog: Permission denied
total 0
server01:/var/log# whoami
root
server01:/var/log# id
uid=0(root) gid=0(root) groups=0(root)
server01:/var/log#


What hell is that? could be a ReiseFs problem (/var is a ReiserFs partition)
Ok, ill try on a ext3 partition:

server01:/var/log# cd /boot
server01:/boot# mkdir a
server01:/boot# ls -laF
total 2368
<snip>
drwxr-xr-x    2 root     root         4096 May  1 12:08 a/
<snip>
server01:/boot# chown mail.adm a
server01:/boot# chmod 750 a
server01:/boot# ls -laF
total 2368
<snip>
drwxr-x---    2 mail     adm          4096 May  1 12:08 a/
<snip>
server01:/boot# ls -laF a
ls: a/.: Permission denied
ls: a/..: Permission denied
total 0
server01:/boot# id
uid=0(root) gid=0(root) groups=0(root)
server01:/boot#


???? WELL?????
reboting to previous kernel version (2.5.8-pre2+1_6_reiserfs patchs)