unison filename case

[L.V.Gandhi <lvgandhi@gmail.com>]

I have etch both in laptop and in my PC. I am using autofs to mount my
external HDD which is formatted vfat.
my local rules for udev mounting are as follows in both machines

lvgandhi@lvghomepc:~$ cat /etc/udev/rules.d/010_local.rules
SUBSYSTEMS=="usb",  DRIVERS=="usb",  ATTRS{product}=="Cruzer Micro",
NAME="%k", SYMLINK="flash", MODE="0775"
BUS=="scsi", SYSFS{model}=="External Drive", KERNEL=="sd?1",
NAME="%k", SYMLINK="ehd"

Further auo.removable has similar lines in both
lvgandhi@lvghomepc:~$ cat /etc/auto.removable
flash   -fstype=vfat,rw,uid=1000,umask=022,posix,shortname=winnt
:/dev/flash
ehd     -fstype=vfat,rw,uid=1000,umask=022,posix,shortname=winnt
  :/dev/ehd

my lvg.prf for doing syn as follows
lvgandhi@lvghomepc:~$ cat .unison/lvg.prf
# Unison preferences file
root = /media/ehd/Lvg
root = /media/wind/Lvg

# to ignore
    ignore = Name *~
    ignore = Name .*~
    ignore = Name *.bak

# to ignore perms
    perms = 0o1600

But in my laptop, when I do sync with unison to external HDD, get no
case conflicts. But when I do sync my PC and External HDD I get case
conflicts.  Further when I do sync with unison both laptop and PC, I
don't get any case conflicts. Problem is with PC and external HDD. Any
clues to avoid this conflict?
-- 
L.V.Gandhi
http://lvgandhi.tripod.com/
linux user No.205042