ipw2100 & Security mode:restricted

[Sergey Smirnov <svs1957 gmail com>]

Hello
I use ad-hoc wi-fi with wep to connect few divice in home network.
One notebook (IBM ThinkPad R40) has Intel Corporation PRO/Wireless LAN 
2100 wi-fi adapter.
When I joint the ad-hoc using networkmanager it set:
Security mode:open instead of Security mode:resticted
and network doesn't work.
If I manually set
iwconfig wlan0 key s:XXXXXXXXXXXXX resticted
network work fine.
After some time NM again reset key mode to open and network down.

I can provide any information you need to solve this bug.
--
Sergey