[iPAQ] Microkbd on H3870

I have tried microkbd for 3800 on my 3870 with Opie.
I run modprobe h3600_microkbd but command 'cat /dev/microkbd/compaq'
say:
cat: compaq: Device or resource busy
and keyborad don't work
why? where I mistake?
I boot my ipaq without console=ttySA0 options.
I have also disabled getty on ttySA0
this is the result of lsmod
--------------
usb-eth 5296 1
sa1100usb_core 16800 0 [usb-eth]
vfat 10752 1 (autoclean)
fat 31344 0 (autoclean) [vfat]
ext3 62192 1 (autoclean)
jbd 43040 1 (autoclean) [ext3]
sa1100_ir 6848 1
ide-disk 8272 2 (autoclean)
ircomm-tty 35824 0 (unused)
ircomm 17024 0 [ircomm-tty]
irda 169584 1 [sa1100_ir ircomm-tty ircomm]
ide-probe-mod 7952 0 (autoclean)
ide-cs 3520 1
ide-mod 41840 2 [ide-disk ide-probe-mod ide-cs]
l2cap 16336 0 (unused)
hci_uart 5936 2
bluez 33808 3 [l2cap hci_uart]
wvlan_cs 33024 1
ds 7920 2 [ide-cs wvlan_cs]
h3600_backpaq 12560 0 (unused)
h3600_microkbd 5328 0 (unused)
ppp_async 7152 0 (unused)
ppp_generic 18032 0 [ppp_async]
slhc 5568 0 [ppp_generic]
uda1341 2944 1 (autoclean)
h3600-uda1341 3376 0
h3600_generic_sleeve 4528 0 (unused)
sa1100_cs 9680 2 [h3600_backpaq h3600_generic_sleeve]
pcmcia_core 39328 0 [ide-cs wvlan_cs ds sa1100_cs]
serial 26688 0 [h3600_generic_sleeve]
h3600-sleeve 5216 0 [h3600_backpaq h3600_generic_sleeve]
sa1100-rtc 5600 0
h3600_ts 11056 1
apm 3568 0 (unused)
h3600_asic 29616 1 (autoclean)
h3600_hal 7216 0 [h3600_backpaq......................
-----------------------
I use kernel 2.4.18-rmk3-hh6.

Pleas help me.

Bye

-- 
Piotti Piero