Unable to mount cifs share

Question

Debian squeeze.

# mount //192.168.2.6/Pub/ m -o guest
mount error(1): Operation not permitted
Refer to the mount.cifs(8) manual page (e.g. man mount.cifs)

I test it on clear system (Debian squeeze x686). mount is ok.

setuid is set. fstab does not contains there share points.

My system:

# ls -l /sbin | grep mount
-rwsr-xr-x 1 root root    32624 Jun  5 00:34 mount.cifs

# ls -l /bin | grep mount
-rwsr-xr-x 1 root root  78616 Jun 20 18:19 mount

Test system:

# ls -l /bin | grep mount
-rwsr-xr-x 1 root root  68316 Июн 20 20:27 mount

# ls -l /sbin | grep mount
-rwsr-xr-x 1 root root    26852 Июн  5 11:43 mount.cifs

What may be wrong?!