mount cifs shows SGID file permission

Issue

• When mounting a Windows shared directory via CIFS, the new file's permission becomes "-rwxrwSrwx" but no problem for folder creation.

# mount -t cifs -o username=xxxx,password=xxxx //windowsser/share /mnt

# ls -al
total 17
drwxrwxrwx  4 root root    0 Jun 16  2011 .
drwxr-xr-x 31 root root 4096 Jun 16 14:24 ..
drwxrwxrwx  2 root root 4096 Jun 16  2011 a
-rwxrwSrwx  1 root root    0 Jun 16 15:02 abcd