pcmcia: atmel_cs drivers: problems with firmware

Hello,
I am running Debian with 2.6.0 kernel on my notebook and have got a 3com 
3crshpw_96 wlan card. I have compiled the atmel wlan drivers supplied 
with the kernel as modules and installed the firmware from Simon Kelleys 
as described. Then I configured cardmgr to use  the atmel_cs module with 
my card and further I changed the location of the sysfs to 'sys' as it 
is on my machin. The configuration for the networkinterface did I make 
in /etc/network/interfaces.
When I insert the card into the pcmcia slot all logs look fine but when 
I try to change the essid for example logoutput sais:
'kernel: eth1: firmware atmel_at76c502_3com.bin is missing, cannot start.'

The next problem occures, when I want to shut down the cardmgr: then I 
get this message all the time:
'unregister_netdevice: usage count = 4 waiting for device to become free'.


Unfortunately I can' test my wlan system properly, becaus I do not have 
any other wlan devices here at home.

I would be pleased if someone could help me.

Sebastian